bugfix(tests): Put BAL back into test fixtures for next bal release (ethereum#2066)

- BAL was removed from block body but we agreed to keep it in the fixtures
  for help with debugging against client BALs to spot diffs.

Author: fselmo

packages/testing/src/execution_testing/fixtures/blockchain.py

@@ -639,6 +639,9 @@ def strip_block_number_computed_field(cls, data: Any) -> Any:
     )
     withdrawals: List[FixtureWithdrawal] | None = None
     execution_witness: WitnessChunk | None = None
+    block_access_list: BlockAccessList | None = Field(
+        None, description="EIP-7928 Block Access List"
+    )
     fork: Fork | None = Field(None, exclude=True)
 
     @computed_field(alias="blocknumber")  # type: ignore[prop-decorator]

packages/testing/src/execution_testing/specs/blockchain.py

@@ -381,6 +381,9 @@ def get_fixture_block(self) -> FixtureBlock | InvalidFixtureBlock:
                 if self.withdrawals is not None
                 else None
             ),
+            block_access_list=self.block_access_list
+            if self.block_access_list
+            else None,
             fork=self.fork,
         ).with_rlp(txs=self.txs)