chore: Remove clippy exception that is no longer needed

[steviez]

Problem

We use the Vec that results from .collect(), so the exception to allow a needless collect is no longer appropriate.

Summary of Changes

Remove outdated clippy exception; noticed this while looking at another review.

[tao-stones]

lgtm - thanks for paying detailed attentions. Just a nit about comment.

[tao-stones]

nit - maybe keep the comment? When I first looked at this code, i thought why collect here, iterator should be enough; then the comment points out it also computes local variables. So in that sense, it's useful; (or refactor Ln 339-340 out)

[steviez]

Fair, my thinking was that with your changes in place, we do explicitly use the tx_costs later on. So even tho we are updating variables as we iterate through, we are going to explicitly use the collected vector as well

[tao-stones]

Gotcha, think my code below can use mapped iterators, doesn't really need vec<Tx_cost> being collected first. But I can see now that comments can be redundant here. No problem to remove it. Can do refactor in other time.

[steviez]

CostModel::calculate_cost() returns a TransactionCost that has non-trivial members (namely that Vec<Pubkey>).

solana/runtime/src/cost_model.rs

Lines 31 to 40 in 2ba7327

	pub struct TransactionCost {
	pub writable_accounts: Vec<Pubkey>,
	pub signature_cost: u64,
	pub write_lock_cost: u64,
	pub data_bytes_cost: u64,
	pub builtins_execution_cost: u64,
	pub bpf_execution_cost: u64,
	pub account_data_size: u64,
	pub is_simple_vote: bool,
	}

Once your newly added feature becomes active, we might iterate through tx_costs (the Vec that results from the collect()) twice. Here

solana/ledger/src/blockstore_processor.rs

Line 350 in 2ba7327

for tx_cost in &tx_costs {

and here:

solana/ledger/src/blockstore_processor.rs

Lines 364 to 365 in 2ba7327

	tx_costs
	.into_iter()

If we skip the collect(), we would have to calculate / allocate a TransactionCost during these two iterations, something like the below right?

sanitized_txs.iter().map(|tx|
    let tx_cost = CostModel::calculate_cost(tx, &bank.feature_set);
)

The implementation of CostModel::calculate_cost() looks non-trivial enough on the surface that it seems avoiding this might be preferable.

In case I'm mistaken and there would be merit to the refactor, agreed that separating into separate PR is the move so I'm going to proceed with this one.