Use safe math when calculating pool tx values

[mattsse]

Describe the feature

This is applied on unvalidated txs:

reth/crates/transaction-pool/src/traits.rs

Lines 920 to 937 in 74dc0e3

	let gas_cost = match &transaction.transaction {
	Transaction::Legacy(t) => U256::from(t.gas_price) * U256::from(t.gas_limit),
	Transaction::Eip2930(t) => U256::from(t.gas_price) * U256::from(t.gas_limit),
	Transaction::Eip1559(t) => U256::from(t.max_fee_per_gas) * U256::from(t.gas_limit),
	Transaction::Eip4844(t) => {
	blob_sidecar = EthBlobTransactionSidecar::Missing;
	U256::from(t.max_fee_per_gas) * U256::from(t.gas_limit)
	}
	#[cfg(feature = "optimism")]
	Transaction::Deposit(_) => U256::ZERO,
	};
	let mut cost: U256 = transaction.value();
	cost += gas_cost;
	if let Some(blob_tx) = transaction.as_eip4844() {
	// add max blob cost
	cost += U256::from(blob_tx.max_fee_per_blob_gas * blob_tx.blob_gas() as u128);
	}

even though invalid transactions will get rejected

these ops can overflow

TODO

use saturating math when calculating cost

saturating is fine because U256::MAX as cost will result in a rejected tx

Additional context

No response

[justcode740]

will take a look