**Describe the bug**
Nimbus VC recognizing time offset followed by missed dutie…s and resulting in a crash.
The VC was running just fine beforehand (no time offsets, no missed duties)
**To Reproduce**
Nimbus is running in Docker with `statusim/nimbus-validator-client:multiarch-v23.7.0` image
Logs:
```
{"log":"INF 2023-08-29 03:56:47.004+00:00 Slot start slot=7204782 epoch=225149 attestationIn=4s blockIn=\u003cunknown\u003e validators=500 good_nodes=2 viable_nodes=0 bad_nodes=4 delay=4ms800us139ns\n","stream":"stdout","time":"2023-08-29T03:56:47.005291
403Z"}
{"log":"INF 2023-08-29 03:56:59.003+00:00 Slot start slot=7204783 epoch=225149 attestationIn=4s blockIn=\u003cunknown\u003e validators=500 good_nodes=2 viable_nodes=0 bad_nodes=4 delay=3ms40us618ns\n","stream":"stdout","time":"2023-08-29T03:56:59.0035494
45Z"}
{"log":"INF 2023-08-29 03:57:04.676+00:00 Beacon node has notable time offset time_offset=596ms699us238ns service=fallback_service node=http://10.12.1.62:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=5 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:04.6765380
71Z"}
{"log":"WRN 2023-08-29 03:57:05.877+00:00 Beacon node has significant time offset time_offset=2s832ms261us118ns service=fallback_service node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:05.878121314Z"}
{"log":"WRN 2023-08-29 03:57:05.877+00:00 Beacon node has enormous time offset time_offset=2s832ms261us118ns service=fallback_service node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:05.878157704Z"}
{"log":"WRN 2023-08-29 03:57:05.878+00:00 Beacon node's clock is out of order, (beacon node is unusable) node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:05.878164366Z"}
{"log":"INF 2023-08-29 03:57:11.542+00:00 Slot start slot=7204784 epoch=225149 attestationIn=4s blockIn=\u003cunknown\u003e validators=500 good_nodes=1 viable_nodes=0 bad_nodes=4 delay=542ms471us289ns\n","stream":"stdout","time":"2023-08-29T03:57:11.542851935Z"}
{"log":"WRN 2023-08-29 03:57:11.670+00:00 Beacon node down reason=\"Beacon node has acceptable time offset;200;checkTimeOffsetStatus()();status-update\" node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:11.670298428Z"}
{"log":"INF 2023-08-29 03:57:12.853+00:00 Beacon node has notable time offset time_offset=913ms852us823ns service=fallback_service node=http://10.12.1.62:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=5 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:12.853519981Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=17 duties_count=3 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007327417Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=23 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007369927Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=30 duties_count=2 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007375277Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=11 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007386307Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=47 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007391237Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=0 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.00739827Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=39 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007406305Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=27 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007472891Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=45 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007479824Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=25 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007518005Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=32 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007534186Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=43 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007586223Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=4 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007598677Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=9 duties_count=2 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007638783Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=38 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007676734Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=1 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007739091Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=55 duties_count=1 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007782843Z"}
{"log":"WRN 2023-08-29 03:57:19.007+00:00 Unable to proceed attestations slot=7204784 committee_index=20 duties_count=2 reason=\"No online beacon node(s)\" service=attestation_service\n","stream":"stdout","time":"2023-08-29T03:57:19.007795578Z"}
{"log":"NOT 2023-08-29 03:57:21.410+00:00 Beacon node is online agent_version=Nimbus/v23.7.0-60f0a2-stateofus node=http://10.12.1.62:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=5 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.41085529Z"}
{"log":"NOT 2023-08-29 03:57:21.428+00:00 Beacon node is online agent_version=Nimbus/v23.7.0-60f0a2-stateofus node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.428594517Z"}
{"log":"NOT 2023-08-29 03:57:21.480+00:00 Beacon node is compatible node=http://10.12.1.62:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=5 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.480468129Z"}
{"log":"NOT 2023-08-29 03:57:21.482+00:00 Beacon node is compatible node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.482453775Z"}
{"log":"NOT 2023-08-29 03:57:21.503+00:00 Beacon node is in sync head_slot=7204784 sync_distance=0 is_optimistic=false node=http://10.12.1.55:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=0 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.503179259Z"}
{"log":"NOT 2023-08-29 03:57:21.505+00:00 Beacon node is in sync head_slot=7204784 sync_distance=0 is_optimistic=false node=http://10.12.1.62:5052[Nimbus/v23.7.0-60f0a2-stateofus] node_index=5 node_roles=AGBSDT\n","stream":"stdout","time":"2023-08-29T03:57:21.505819437Z"}
{"log":"INF 2023-08-29 03:57:23.322+00:00 Slot start slot=7204785 epoch=225149 attestationIn=4s blockIn=\u003cunknown\u003e validators=500 good_nodes=2 viable_nodes=0 bad_nodes=4 delay=322ms496us772ns\n","stream":"stdout","time":"2023-08-29T03:57:23.322832844Z"}
{"log":"WRN 2023-08-29 03:57:23.328+00:00 Unable to publish sync committee messages and contributions in time slot=7204784 timeout=11s456ms906us700ns service=sync_committee_service\n","stream":"stdout","time":"2023-08-29T03:57:23.328831842Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-libp2p/libp2p/protocols/pubsub/pubsub.nim(865) main\n","stream":"stderr","time":"2023-08-29T03:57:25.021216691Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-libp2p/libp2p/protocols/pubsub/pubsub.nim(858) NimMain\n","stream":"stderr","time":"2023-08-29T03:57:25.021256956Z"}
{"log":"/home/user/nimbus-eth2/beacon_chain/nimbus_validator_client.nim(521) main\n","stream":"stderr","time":"2023-08-29T03:57:25.021261705Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncloop.nim(1504) waitFor\n","stream":"stderr","time":"2023-08-29T03:57:25.021265562Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncloop.nim(258) poll\n","stream":"stderr","time":"2023-08-29T03:57:25.021268959Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncfutures2.nim(318) futureContinue\n","stream":"stderr","time":"2023-08-29T03:57:25.021272505Z"}
{"log":"/home/user/nimbus-eth2/beacon_chain/validator_client/api.nim(233) getAttesterDuties\n","stream":"stderr","time":"2023-08-29T03:57:25.021276212Z"}
{"log":"/home/user/nimbus-eth2/beacon_chain/validator_client/api.nim(117) apiResponseOr\n","stream":"stderr","time":"2023-08-29T03:57:25.02127999Z"}
{"log":"/home/user/nimbus-eth2/beacon_chain/validator_client/api.nim(120) apiResponseOr\n","stream":"stderr","time":"2023-08-29T03:57:25.021283446Z"}
{"log":"/home/user/nimbus-eth2/vendor/nimbus-build-system/vendor/Nim/lib/system/assertions.nim(38) failedAssertImpl\n","stream":"stderr","time":"2023-08-29T03:57:25.021287013Z"}
{"log":"/home/user/nimbus-eth2/vendor/nimbus-build-system/vendor/Nim/lib/system/assertions.nim(28) raiseAssert\n","stream":"stderr","time":"2023-08-29T03:57:25.021290509Z"}
{"log":"/home/user/nimbus-eth2/vendor/nimbus-build-system/vendor/Nim/lib/system/fatal.nim(54) sysFatal\n","stream":"stderr","time":"2023-08-29T03:57:25.021294137Z"}
{"log":"[[reraised from:\n","stream":"stderr","time":"2023-08-29T03:57:25.021297473Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-libp2p/libp2p/protocols/pubsub/pubsub.nim(865) main\n","stream":"stderr","time":"2023-08-29T03:57:25.021300749Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-libp2p/libp2p/protocols/pubsub/pubsub.nim(858) NimMain\n","stream":"stderr","time":"2023-08-29T03:57:25.021304026Z"}
{"log":"/home/user/nimbus-eth2/beacon_chain/nimbus_validator_client.nim(521) main\n","stream":"stderr","time":"2023-08-29T03:57:25.021307452Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncloop.nim(1504) waitFor\n","stream":"stderr","time":"2023-08-29T03:57:25.021310929Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncloop.nim(258) poll\n","stream":"stderr","time":"2023-08-29T03:57:25.021314245Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncfutures2.nim(318) futureContinue\n","stream":"stderr","time":"2023-08-29T03:57:25.021317641Z"}
{"log":"/home/user/nimbus-eth2/vendor/nim-chronos/chronos/asyncmacro2.nim(197) getAttesterDuties\n","stream":"stderr","time":"2023-08-29T03:57:25.021320867Z"}
{"log":"]]\n","stream":"stderr","time":"2023-08-29T03:57:25.021324264Z"}
{"log":"Error: unhandled exception: /home/user/nimbus-eth2/beacon_chain/validator_client/api.nim(120, 13) `not (future.cancelled())` [AssertionDefect]\n","stream":"stderr","time":"2023-08-29T03:57:25.02132757Z"}
```