Merge pull request #10401 from jdufresne/files-to-clear

Remove unused ConfigurationMixin._files_to_clear

Author: sbidoul

news/06aa831e-3893-4502-b438-ef3c94e8227a.trivial.rst

@@ -19,11 +19,6 @@ def setup(self):
         self.configuration = pip._internal.configuration.Configuration(
             isolated=False,
         )
-        self._files_to_clear = []
-
-    def teardown(self):
-        for fname in self._files_to_clear:
-            fname.stop()
 
     def patch_configuration(self, variant, di):
         old = self.configuration._load_config_files