Added some test cases to the PR that directly trigger the issue, specifically this one:

    def test_entered_path_does_not_keep_open(self):
        # This is what certifi does on import to make its bundle
        # available for the process duration.
        c = resources.path('ziptestdata', 'binary.file').__enter__()
        self.zip_path.unlink()

All the tests I added pass on 3.9 (with minor tweaks for moved test utils).

To unblock the upcoming releases, I'm going to do the backports first and leave this as a release blocker for 3.10.