CI builds broken for windows-2022, mingw64, msys2

[darbyjohnston]

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[x] Build problem
[ ] Incorrect Functionality or bug
[ ] New feature or functionality

Description

It looks like CI builds are failing on windows-2022, mingw64, msys2:
https://github.com/AcademySoftwareFoundation/OpenTimelineIO/actions/runs/9359154592/job/25762376998?pr=1755

The error happens in the "Run check-manifest and lint check" stage, with an error about distlib not being found:

ModuleNotFoundError: No module named 'pip._vendor.distlib'

@markreidvfx I think you added support for msys2 to the CI, any thoughts on the error?