Address review comment

Author: ronaldoussoren

Lib/test/test_import/__init__.py

@@ -2728,6 +2728,7 @@ def assert_importing_possible(self, name):
         exec(f"from {name} import SPAM", values, values)
         try:
             self.assertEqual(values["SPAM"], "spam")
+            self.assertIn(normalized, sys.modules)
         finally:
             del sys.modules[normalized]