CfgEnv.chain_id should be u64

[DaniPopes]

The only check done is by converting TxEnv.chain_id to U256 which is redundant:

revm/crates/primitives/src/env.rs

Lines 309 to 314 in 4272535

	// Check if the transaction's chain id is correct
	if let Some(tx_chain_id) = self.tx.chain_id {
	if U256::from(tx_chain_id) != self.cfg.chain_id {
	return Err(InvalidTransaction::InvalidChainId);
	}
	}

It can be converted to U256 directly in the CHAINID opcode with U256::from, since it's very cheap.