Check empty EL reqs for OpEngineValidator

[emhane]

Describe the feature

Check that the param Requests are always empty in impl of EngineValidator for OpEngineValidator

Blocked by #13849

Additional context

Ref ethereum-optimism/specs#506

[emhane]

@meyer9 would you like to impl this? would wrap up eip7685 impl on op-reth end

[emhane]

requires moving the default impl of EngineValidator::validate_execution_requests into an impl on EthereumEngineValidator

reth/crates/ethereum/engine-primitives/src/lib.rs

Lines 110 to 129 in cc8558f

	impl<Types> EngineValidator<Types> for EthereumEngineValidator
	where
	Types: EngineTypes<PayloadAttributes = EthPayloadAttributes>,
	{
	fn validate_version_specific_fields(
	&self,
	version: EngineApiMessageVersion,
	payload_or_attrs: PayloadOrAttributes<'_, EthPayloadAttributes>,
	) -> Result<(), EngineObjectValidationError> {
	validate_version_specific_fields(self.chain_spec(), version, payload_or_attrs)
	}
	fn ensure_well_formed_attributes(
	&self,
	version: EngineApiMessageVersion,
	attributes: &EthPayloadAttributes,
	) -> Result<(), EngineObjectValidationError> {
	validate_version_specific_fields(self.chain_spec(), version, attributes.into())
	}
	}

and then custom impl on OpEngineValidator checking for empty requests

reth/crates/optimism/node/src/engine.rs

Lines 104 to 161 in cc8558f

	impl<Types> EngineValidator<Types> for OpEngineValidator
	where
	Types: EngineTypes<PayloadAttributes = OpPayloadAttributes>,
	{
	fn validate_version_specific_fields(
	&self,
	version: EngineApiMessageVersion,
	payload_or_attrs: PayloadOrAttributes<'_, OpPayloadAttributes>,
	) -> Result<(), EngineObjectValidationError> {
	validate_withdrawals_presence(
	self.chain_spec(),
	version,
	payload_or_attrs.message_validation_kind(),
	payload_or_attrs.timestamp(),
	payload_or_attrs.withdrawals().is_some(),
	)?;
	validate_parent_beacon_block_root_presence(
	self.chain_spec(),
	version,
	payload_or_attrs.message_validation_kind(),
	payload_or_attrs.timestamp(),
	payload_or_attrs.parent_beacon_block_root().is_some(),
	)
	}
	fn ensure_well_formed_attributes(
	&self,
	version: EngineApiMessageVersion,
	attributes: &OpPayloadAttributes,
	) -> Result<(), EngineObjectValidationError> {
	validate_version_specific_fields(self.chain_spec(), version, attributes.into())?;
	if attributes.gas_limit.is_none() {
	return Err(EngineObjectValidationError::InvalidParams(
	"MissingGasLimitInPayloadAttributes".to_string().into(),
	))
	}
	if self
	.chain_spec()
	.is_holocene_active_at_timestamp(attributes.payload_attributes.timestamp)
	{
	let (elasticity, denominator) =
	attributes.decode_eip_1559_params().ok_or_else(|| {
	EngineObjectValidationError::InvalidParams(
	"MissingEip1559ParamsInPayloadAttributes".to_string().into(),
	)
	})?;
	if elasticity != 0 && denominator == 0 {
	return Err(EngineObjectValidationError::InvalidParams(
	"Eip1559ParamsDenominatorZero".to_string().into(),
	))
	}
	}
	Ok(())
	}
	}

[meyer9]

yup, I can take this one!