publishBlockV2 fails gossip validation for valid block
**Describe the bug**

I am testing Nimbus BN with Lodestar VC on Kurtosis. The previous issue (https://github.com/status-im/nimbus-eth2/issues/6176) is now fixed on unstable branch  (https://github.com/status-im/nimbus-eth2/commit/c5f04dd237377c55afba26369c9ece6117462ead) but there is another issue during block publishing which only happens with Nimbus from `unstable` branch, but works on `stable` branch.

This is the error logged on the Nimbus BN
```
WRN 2024-04-16 12:01:56.939+00:00 Block failed validation                    topics="beacval" blockRoot=00000000 blck="(slot: 1, proposer_index: 1147, parent_root: \"515bb412\", state_root: \"145b6448\", eth1data: (deposit_root: d70a234731285c6804c2a4f56711ddb8c82c99740f207854891028af34e27e5e, deposit_count: 0, block_hash: 6903b6723e1921a599446c55bbb140dac226f150d5ba737bd94456171c8b3ad9), graffiti: \"5-geth-nimbus-lodestar\", proposer_slashings_len: 0, attester_slashings_len: 0, attestations_len: 0, deposits_len: 0, voluntary_exits_len: 0, sync_committee_participants: 0, block_number: 1, block_hash: \"0x8e132997d62f55007d8a1d67fe7eca60c5f2f738dbe47e1790f582db2cf25efe\", parent_hash: \"0x6903b6723e1921a599446c55bbb140dac226f150d5ba737bd94456171c8b3ad9\", fee_recipient: \"0x8943545177806ed17b9f23f0a21ee5948ecaa776\", bls_to_execution_changes_len: 0, blob_kzg_commitments_len: 0)" signature=aefb60f2 error="(Reject, \"BeaconBlock: Invalid proposer signature\")"

```

From the looks of it, it seems like the block is failing gossip validation, the publish request done by Lodestar looks like this
```
Apr 16 12:01:56.928 2024 REQUEST /eth/v2/beacon/blocks?broadcast_validation=gossip
[38;5;6m{[39m
[38;5;6m  "message": {[39m
[38;5;6m    "slot": "1",[39m
[38;5;6m    "proposer_index": "1147",[39m
[38;5;6m    "parent_root": "0x515bb41259ab0902ad3e5ec658327cd25f387dfd5cf7763f7cd593060e213e7f",[39m
[38;5;6m    "state_root": "0x145b6448f76dd454df1b339ae4731e6e30ce73b2c8ea4a008f290899de2c339a",[39m
[38;5;6m    "body": {[39m
[38;5;6m      "randao_reveal": "0x87b1cce981a31d800402667eee9c7de84de72c0a01ffbe8744106aed6c50660faa5faed1e5846a08207202784bb28105054d9425621e8b56db41dde74d2b6ab775f4dac84bb43593db34f65570ba296b025a86da859dd9a5097c4a083b0932c5",[39m
[38;5;6m      "eth1_data": {[39m
[38;5;6m        "deposit_root": "0xd70a234731285c6804c2a4f56711ddb8c82c99740f207854891028af34e27e5e",[39m
[38;5;6m        "deposit_count": "0",[39m
[38;5;6m        "block_hash": "0x6903b6723e1921a599446c55bbb140dac226f150d5ba737bd94456171c8b3ad9"[39m
[38;5;6m      },[39m
[38;5;6m      "graffiti": "0x352d676574682d6e696d6275732d6c6f64657374617200000000000000000000",[39m
[38;5;6m      "proposer_slashings": [],[39m
[38;5;6m      "attester_slashings": [],[39m
[38;5;6m      "attestations": [],[39m
[38;5;6m      "deposits": [],[39m
[38;5;6m      "voluntary_exits": [],[39m
[38;5;6m      "sync_aggregate": {[39m
[38;5;6m        "sync_committee_bits": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",[39m
[38;5;6m        "sync_committee_signature": "0xc00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"[39m
[38;5;6m      },[39m
[38;5;6m      "execution_payload": {[39m
[38;5;6m        "parent_hash": "0x6903b6723e1921a599446c55bbb140dac226f150d5ba737bd94456171c8b3ad9",[39m
[38;5;6m        "fee_recipient": "0x8943545177806ED17B9F23F0a21ee5948eCaa776",[39m
[38;5;6m        "state_root": "0xaa65ab8098cfddd2a7e893480584e2a331ea7be5a91afede0bce3b8e4515e643",[39m
[38;5;6m        "receipts_root": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",[39m
[38;5;6m        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",[39m
[38;5;6m        "prev_randao": "0x6903b6723e1921a599446c55bbb140dac226f150d5ba737bd94456171c8b3ad9",[39m
[38;5;6m        "block_number": "1",[39m
[38;5;6m        "gas_limit": "25024413",[39m
[38;5;6m        "gas_used": "0",[39m
[38;5;6m        "timestamp": "1713268916",[39m
[38;5;6m        "extra_data": "0xd883010d0e846765746888676f312e32312e37856c696e7578",[39m
[38;5;6m        "base_fee_per_gas": "875000000",[39m
[38;5;6m        "block_hash": "0x8e132997d62f55007d8a1d67fe7eca60c5f2f738dbe47e1790f582db2cf25efe",[39m
[38;5;6m        "transactions": [],[39m
[38;5;6m        "withdrawals": [][39m
[38;5;6m      },[39m
[38;5;6m      "bls_to_execution_changes": [][39m
[38;5;6m    }[39m
[38;5;6m  },[39m
[38;5;6m  "signature": "0xaefb60f20fce54c1c9a4669f2a5d7b9fda279b602b60221d57befcb2d78358232542494ab89530a21d72229784e1b3d4009f0f04967a0e19ead7cb45a9f38739cc17cdcdd148701d7160886816432e183339ecc715f2d4203c8cf19d9366e800"[39m
[38;5;6m}[39m
```

And the response from Nimbus BN 
```
Apr 16 12:01:56.939 2024 RESPONSE (status 503 Service Unavailable) 
[38;5;2m{[39m
[38;5;2m  "code": 503,[39m
[38;5;2m  "message": "Beacon node is currently syncing and not serving request on that endpoint",[39m
[38;5;2m  "stacktraces": [[39m
[38;5;2m    "BeaconBlock: Invalid proposer signature"[39m
[38;5;2m  ][39m
[38;5;2m}[39m
```




**To Reproduce**
Steps to reproduce the behavior:

Kurtosis config file

```yaml
participants:
# ...
  - el_type: geth
    el_image: ethereum/client-go:stable
    cl_type: nimbus
    cl_image: ethpandaops/nimbus-eth2:unstable-c5f04dd
    vc_type: lodestar
    vc_image: chainsafe/lodestar:next
    # vc_image: nflaig/lodestar:use-publish-v1 <-- using publish v1 api solves the issue
    count: 1
# ...
```

**Additional context**

The issue seems to be related to `publishBlockV2` only, forcing Lodestar VC to use `publishBlock` (v1) resolves the issue.  
