gh-143641: Make ready_to_import always remove tempdir from sys.path (GH-143642)

Make ready_to_import always remove tempdir from sys.path
(cherry picked from commit e7f5ffa)

Co-authored-by: Jeong, YunWon <69878+youknowone@users.noreply.github.com>

Author: youknowone

Lib/test/support/import_helper.py

@@ -303,8 +303,8 @@ def ready_to_import(name=None, source=""):
         try:
             sys.path.insert(0, tempdir)
             yield name, path
-            sys.path.remove(tempdir)
         finally:
+            sys.path.remove(tempdir)
             if old_module is not None:
                 sys.modules[name] = old_module
             else: