revive/fix: Remove double tax on eth_call weight

[lexnv]

This PR aligns the eth_call with eth_instantiate_with_code in terms of weight.

@pgherveou noticed that we are double taxing the eth_call in terms of weight:

• (I) we are adding the #pallet::weight on the encoded tx length
• (II) we are adding the same weight again via .saturating_add(T::WeightInfo::on_finalize_block_per_tx(encoded_length))

This PR removes the weight from (II) and relies on the #pallet::weight entirely.

cc @pgherveou @lrubasze 🙏

[lexnv]

/cmd prdoc --audience node_dev --bump patch

[paritytech-workflow-stopper]

All GitHub workflows were cancelled due to failure one of the required jobs.
Failed workflow url: https://github.com/paritytech/polkadot-sdk/actions/runs/18845187888
Failed job name: test-linux-stable

[lrubasze]

LGTM

[pgherveou]

let me do that as part of #10120
I think we also need update the eth_instantiate_with_code weight attribute

[pgherveou]

will port the patch here #10120