Remove extensive and superflous gas checks in EIP-8038 tests

[danceratopz]

Suggested clean-up by @marioevz following merge of the EIP-8038 tests into https://github.com/ethereum/execution-specs/tree/eips/amsterdam/eip-2780-8038

See:

• test(amsterdam): add EIP-8038 state-access gas cost tests #3033 (comment)
• fix(tests): measure on-chain SSTORE regular gas and warm the warm rows CPerezz/execution-specs#7 (comment)