Use per-test temp files in test fixtures

The `filepath_h5mu`/`filepath_hdf5` fixtures were module-scoped, so a shared
file path was reused across tests. Under the template's parallel test runner
(`pytest -n auto`) two workers wrote the same HDF5 file and collided
(`BlockingIOError: unable to lock file`). Scope them per function with unique
`tmp_path` files instead.

Author: Zethson

tests/conftest.py

@@ -2,14 +2,14 @@
 import scanpy as sc  # type: ignore[import-untyped]
 
 
-@pytest.fixture(scope="module")
-def filepath_h5mu(tmpdir_factory):
-    yield str(tmpdir_factory.mktemp("tmp_test_dir").join("test.h5mu"))
+@pytest.fixture
+def filepath_h5mu(tmp_path):
+    yield str(tmp_path / "test.h5mu")
 
 
-@pytest.fixture(scope="module")
-def filepath_hdf5(tmpdir_factory):
-    yield str(tmpdir_factory.mktemp("tmp_mofa_dir").join("mofa_pytest.hdf5"))
+@pytest.fixture
+def filepath_hdf5(tmp_path):
+    yield str(tmp_path / "mofa_pytest.hdf5")
 
 
 @pytest.fixture(scope="module")