bpo-44808: Fix test_inspect in refleak mode (GH-27544)

(cherry picked from commit 626d397cc1612ea5eef153dd910834c2ee00ddbd)

Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index b664c14..157f315 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -587,11 +587,12 @@ def test_getsource_on_code_object(self):
 
 class TestGetsourceInteractive(unittest.TestCase):
     def tearDown(self):
-        mod.ParrotDroppings.__module__ = mod
+        mod.ParrotDroppings.__module__ = self.mod
         sys.modules['__main__'] = self.main
 
     def test_getclasses_interactive(self):
         self.main = sys.modules['__main__']
+        self.mod = mod.ParrotDroppings.__module__
         class MockModule:
             __file__ = None
         sys.modules['__main__'] = MockModule