gh-96624: Fix test_dotted_but_module_not_loaded in testpatch.py

[sweeneyde]

This seems to reflect better the original meaning of the code before c735d54, and it should fix the consistent warning on most refleak buildbots.

• Issue: python -m test test_unitttest -R3:3 fails #96624

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @sweeneyde for commit dff1c60 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[sweeneyde]

All of the refleak buildbots that ran no longer have the warnings about failing and re-trying test_unittest.

Unfortunately, they all emit at least one other warning (#96696), so they're still "orange", not green.

[ezio-melotti]

LGTM.

This seems to reflect better the original meaning of the code before c735d54,

Specifically this bit: c735d54#diff-a166f2dc69b03117686d52e8c67698b174f612d6e57c692a74d5f4cce1798c84L1922-L1926

         # make sure it's there
-        import unittest.test.testmock.support
+        import test.test_unittest.testmock.support
         # now make sure it's not:
         with patch.dict('sys.modules'):
-            del sys.modules['unittest.test.testmock.support']
-            del sys.modules['unittest.test.testmock']
-            del sys.modules['unittest.test']
+            del sys.modules['test.test_unittest.testmock.support']
+            del sys.modules['test.test_unittest.testmock']
+            del sys.modules['test.test_unittest']
             del sys.modules['unittest']

[cjw296]

Looks good, thanks!