Microsoft Store Pythons do not always register themselves in the
registry, so we port
<https://github.com/python/cpython/blob/58ce131037ecb34d506a613f21993cde2056f628/PC/launcher2.c#L1744>
and look them up on the filesystem in known locations.
## Test Plan
So far I've confirmed that we find a store Python when I use `cargo run
python list`, can we make this a part of any of the platform tests
maybe?
konsti