feat(tests): add execution-dominant EIP-7981 block gas coverage

[spencer-tb]

Description

Add a standalone EIP-7981 test for execution-dominant block gas accounting with nonzero state gas. A storage write is funded from an over-cap reservoir, and additional execution work makes execution gas exceed both the calldata floor and state gas.

For transaction types 1 and 2, assert the storage update, successful receipt with execution plus state gas, and a block header charging execution gas alone. This catches an implementation that uses only the floor for the execution dimension or includes state gas in the execution charge.

This is an independent test addition on top of 7981-improve-tests. It contains no changes from the review-fix branch.

Validation:

• 553/553 EIP-7981 fill cases pass at Amsterdam, including six cases from the new test.
• just static passes.
• A temporary mutation forcing the execution dimension to the floor fails all four new blockchain/Engine header checks.
• Client consumption has not been run for the new cases.

Related Issues or PRs

• Targets the branch of feat(tests): complete EIP-7981 coverage and testing checklist ethereum/execution-specs#3537

Checklist

• Ran fast static checks to avoid CI fails, see Code Standards & Verifying Changes: just static
• PR title has the form <type>(<area>): <title>, where <type> and <area> come from an appropriate C-<type>, respectively A-<area>, label. The title should match the target squash commit message.

Cute Animal Picture