pytest: Fix warning regarding usefixtures (#519)

Author: tony

CHANGES

@@ -14,6 +14,10 @@ $ pip install --user --upgrade --pre libtmux
 
 <!-- Maintainers and contributors: Insert change notes for the next release above -->
 
+### Tests
+
+- pytest: Fix `usefixture` warning (#519)
+
 ## libtmux 0.27.1 (2024-02-07)
 
 ### Packaging

conftest.py

@@ -47,12 +47,19 @@ def set_home(
     monkeypatch.setenv("HOME", str(user_path))
 
 
+@pytest.fixture(autouse=True, scope="function")
+def setup_fn(
+    clear_env: None,
+) -> None:
+    """Function-level test configuration fixtures for pytest."""
+    pass
+
+
 @pytest.fixture(autouse=True, scope="session")
-@pytest.mark.usefixtures("clear_env")
-def setup(
+def setup_session(
     request: pytest.FixtureRequest,
     config_file: pathlib.Path,
 ) -> None:
-    """Configure test fixtures for pytest."""
+    """Session-level test configuration for pytest."""
     if USING_ZSH:
         request.getfixturevalue("zshrc")