N/A
In #8101 , when we modified the logic to get the proposer index post fulu, we seem to have missed advancing the state at the fork boundaries to get the right `Fork` for signature verification.
This led to lighthouse failing all gossip verification right after transitioning to fulu that was observed on the holesky shadow fork
```
Sep 26 14:24:00.088 DEBUG Rejected gossip block error: "InvalidSignature(ProposerSignature)", graffiti: "grandine-geth-super-1", slot: 640
Sep 26 14:24:00.099 WARN Could not verify block for gossip. Rejecting the block error: InvalidSignature(ProposerSignature)
```
I'm not completely sure this is the correct fix, but this fixes the issue with `InvalidProposerSignature` on the holesky shadow fork.
Thanks to @eserilev for helping debug this
Co-Authored-By: Pawan Dhananjay <pawandhananjay@gmail.com>
edcfee636c