chore(tests): set tx gas limit to 2^24 (#1882)

* chore(tests): set tx gas limit to 2^24.

* chore(tests|forks): fix tx gas limit change.

Author: spencer-tb

docs/CHANGELOG.md

@@ -96,7 +96,7 @@ Users can select any of the artifacts depending on their testing needs for their
 - ✨ EIP-7594: Sanity test cases to send blob transactions and verify `engine_getBlobsVX` using the `execute` command ([#1644](https://github.com/ethereum/execution-spec-tests/pull/1644)).
 - 🔀 Refactored EIP-145 static tests into python ([#1683](https://github.com/ethereum/execution-spec-tests/pull/1683)).
 - ✨ EIP-7823, EIP-7883: Add test cases for ModExp precompile gas-cost updates and input limits on Osaka ([#1579](https://github.com/ethereum/execution-spec-tests/pull/1579), [#1729](https://github.com/ethereum/execution-spec-tests/pull/1729)).
-- ✨ [EIP-7825](https://eips.ethereum.org/EIPS/eip-7825): Add test cases for the transaction gas limit of 30M gas ([#1711](https://github.com/ethereum/execution-spec-tests/pull/1711)).
+- ✨ [EIP-7825](https://eips.ethereum.org/EIPS/eip-7825): Add test cases for the transaction gas limit of 2^24 gas ([#1711](https://github.com/ethereum/execution-spec-tests/pull/1711), [#1882](https://github.com/ethereum/execution-spec-tests/pull/1882)).
 - ✨ [EIP-7951](https://eips.ethereum.org/EIPS/eip-7951): add test cases for `P256VERIFY` precompile to support secp256r1 curve [#1670](https://github.com/ethereum/execution-spec-tests/pull/1670).
 - ✨ Introduce blockchain tests for benchmark to cover the scenario of pure ether transfers [#1742](https://github.com/ethereum/execution-spec-tests/pull/1742).
 - ✨ [EIP-7934](https://eips.ethereum.org/EIPS/eip-7934): Add test cases for the block RLP max limit of 10MiB ([#1730](https://github.com/ethereum/execution-spec-tests/pull/1730)).

src/ethereum_test_forks/forks/forks.py

@@ -1378,7 +1378,7 @@ def engine_get_blobs_version(cls, block_number: int = 0, timestamp: int = 0) ->
     @classmethod
     def transaction_gas_limit_cap(cls, block_number: int = 0, timestamp: int = 0) -> int | None:
         """At Osaka, transaction gas limit is capped at 30 million."""
-        return 30_000_000
+        return 16_777_216
 
     @classmethod
     def block_rlp_size_limit(cls, block_number: int = 0, timestamp: int = 0) -> int | None:

tests/osaka/eip7825_transaction_gas_limit_cap/test_tx_gas_limit.py

@@ -28,7 +28,7 @@
 REFERENCE_SPEC_GIT_PATH = "EIPS/eip-7825.md"
 REFERENCE_SPEC_VERSION = "47cbfed315988c0bd4d10002c110ae402504cd94"
 
-TX_GAS_LIMIT = 30_000_000
+TX_GAS_LIMIT = 2**24  # 16,777,216
 BLOB_COMMITMENT_VERSION_KZG = 1
 
 
@@ -125,8 +125,8 @@ def test_transaction_gas_limit_cap_at_transition(
     """
     Test transaction gas limit cap behavior at the Osaka transition.
 
-    Before timestamp 15000: No gas limit cap (transactions with gas > 30M are valid)
-    At/after timestamp 15000: Gas limit cap of 30M is enforced
+    Before timestamp 15000: No gas limit cap (transactions with gas > 2^24 are valid)
+    At/after timestamp 15000: Gas limit cap of 2^24 is enforced
     """
     sender = pre.fund_eoa()
     contract_address = pre.deploy_contract(
@@ -137,7 +137,7 @@ def test_transaction_gas_limit_cap_at_transition(
     if pre_cap is None:
         pre_cap = TX_GAS_LIMIT
 
-    # Transaction with gas limit above 30M
+    # Transaction with gas limit above the cap before transition
     high_gas_tx = Transaction(
         ty=0,  # Legacy transaction
         to=contract_address,