Enforce ruff/flake8-pytest-style rule PT001

PT001 Use `@pytest.fixture` over `@pytest.fixture()`

Author: DimitriPapadopoulos

numcodecs/tests/test_entrypoints.py

@@ -8,7 +8,7 @@
 here = os.path.abspath(os.path.dirname(__file__))
 
 
-@pytest.fixture()
+@pytest.fixture
 def set_path():
     sys.path.append(here)
     numcodecs.registry.run_entrypoints()