test_tkinter leaks references on Windows

* Latest successful build: https://buildbot.python.org/all/#/builders/920/builds/543
* First failing build: https://buildbot.python.org/all/#/builders/920/builds/549

```
test_tkinter leaked [336, 336, 337] references, sum=1009
test_tkinter leaked [151, 151, 152] memory blocks, sum=454
```


### Linked PRs
* gh-111533
* gh-111535
* gh-111536