#15872: Some more Windows related tuning to shutil.rmtree tests
#15872: Some more Windows related tuning to shutil.rmtree tests

Turns out, the snakebite bots behave also their peculiarities.

I'm really not proud of this stream of commits. :(

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator