private static BlockHeaderValidator.Builder getBlockHeaderValidator(
      final FeeMarket feeMarket,
      final GasCalculator gasCalculator,
      final GasLimitCalculator gasLimitCalculator) {
    return MergeValidationRulesetFactory.mergeBlockHeaderValidator(feeMarket);
  }
Apply Paris specific modifications because the Merge Transition code does not utilise {@link
org.hyperledger.besu.ethereum.mainnet.MainnetProtocolSpecFactory.parisDefinition} until the
shanghaiDefinition is utilised. This is due to the way the Transition works via TTD rather than
via a blockNumber so it can't be looked up in the schedule.
consensus/merge/src/main/java/org/hyperledger/besu/consensus/merge/MergeProtocolSchedule.java