Minimal effort for Python 2

Don't fix what's not reported.

Author: uranusjr

src/pip/_internal/utils/temp_dir.py

@@ -203,8 +203,7 @@ def cleanup(self):
         # natively for paths, and the bytes-text conversion omission avoids
         # errors caused by the environment configuring encodings incorrectly.
         if WINDOWS:
-            encoding = sys.getfilesystemencoding()
-            rmtree(ensure_text(self._path, encoding=encoding))
+            rmtree(ensure_text(self._path))
         else:
             rmtree(self._path)