Add gas_used to State Test fixtures

[marioevz]

          Added a comment, but I'm thinking that, to make it easier when debugging the test, we could include the `gas_used` field in the state test fixture.

Potentially here:

execution-spec-tests/src/ethereum_test_fixtures/state.py

Lines 86 to 94 in 4891ac7

	class FixtureForkPost(CamelModel):
	"""Type used to describe the post state of a single Fork."""
	state_root: Hash = Field(..., alias="hash")
	logs_hash: Hash = Field(..., alias="logs")
	tx_bytes: Bytes = Field(..., alias="txbytes")
	indexes: FixtureForkPostIndexes = Field(default_factory=FixtureForkPostIndexes)
	state: Alloc
	expect_exception: TransactionExceptionInstanceOrList | None = None

Originally posted by @marioevz in #1071 (comment)