Refactor: test code.

Author: ya7010

tests/test_config.py

@@ -38,4 +38,5 @@ def test_jinja(self):
 
     @pytest.mark.parametrize("config_file", (DATA_DIR / "config").iterdir())
     def test_config_file(self, config_file):
-        load(config_file.open())
+        with open(config_file) as file:
+            load(file)