Remove stale comment on latest_execution_payload_header in Electra (#3929)

Author: nflaig

specs/electra/beacon-chain.md

@@ -362,7 +362,7 @@ class BeaconState(Container):
     current_sync_committee: SyncCommittee
     next_sync_committee: SyncCommittee
     # Execution
-    latest_execution_payload_header: ExecutionPayloadHeader  # [Modified in Electra:EIP6110:EIP7002]
+    latest_execution_payload_header: ExecutionPayloadHeader
     # Withdrawals
     next_withdrawal_index: WithdrawalIndex
     next_withdrawal_validator_index: ValidatorIndex