Remove json fixture cache

It was causing test failures after a VMTest move, and didn't seem to be
providing a measurable benefit (perhaps even a slowdown).

The test failure showed up as trying to load the files in the old VMTest
location in ethereum/tests. Those file paths were being loaded out of a
stale cache.

Author: carver

eth/tools/fixtures/generation.py

@@ -1,5 +1,4 @@
 import hashlib
-import os
 
 from typing import (
     Any,
@@ -14,7 +13,6 @@
 
 from .loading import (
     find_fixtures,
-    find_fixture_files,
 )
 
 
@@ -59,31 +57,8 @@ def generate_fixture_tests(metafunc: Any,
        fixtures (such as expanding the statetest fixtures to be multiple tests for
        each fork.
     """
-    fixture_namespace = os.path.basename(base_fixture_path)
-
     if 'fixture_data' in metafunc.fixturenames:
-        all_fixture_paths = find_fixture_files(base_fixture_path)
-        current_file_hash = get_fixtures_file_hash(all_fixture_paths)
-
-        data_cache_key = f'pyevm/statetest/fixtures/{fixture_namespace}/data'
-        file_hash_cache_key = f'pyevm/statetest/fixtures/{fixture_namespace}/data-hash'
-
-        cached_file_hash = metafunc.config.cache.get(file_hash_cache_key, None)
-        cached_fixture_data = metafunc.config.cache.get(data_cache_key, None)
-
-        bust_cache = any((
-            cached_file_hash is None,
-            cached_fixture_data is None,
-            cached_file_hash != current_file_hash,
-        ))
-
-        if bust_cache:
-            all_fixtures = find_fixtures(base_fixture_path)
-
-            metafunc.config.cache.set(data_cache_key, all_fixtures)
-            metafunc.config.cache.set(file_hash_cache_key, current_file_hash)
-        else:
-            all_fixtures = cached_fixture_data
+        all_fixtures = find_fixtures(base_fixture_path)
 
         if not all_fixtures:
             raise AssertionError(

eth/tools/fixtures/loading.py

@@ -101,7 +101,7 @@ def filter_fixtures(all_fixtures: Iterable[Any],
             if mark:
                 yield pytest.param(
                     (fixture_path, *fixture_data[1:]),
-                    marks=mark,
+                    marks=mark,  # type: ignore  # we don't annotate the test code that calls this
                 )
                 continue