Add type hint for a use of Pytest's tmp_path_factory (#12791)

Author: adamtheturtle

sphinx/testing/fixtures.py

@@ -239,7 +239,7 @@ def if_graphviz_found(app: SphinxTestApp) -> None:  # NoQA: PT004
 
 
 @pytest.fixture(scope='session')
-def sphinx_test_tempdir(tmp_path_factory: Any) -> Path:
+def sphinx_test_tempdir(tmp_path_factory: pytest.TempPathFactory) -> Path:
     """Temporary directory."""
     return tmp_path_factory.getbasetemp()