Add a `UV_BOOTSTRAP_DIR` option to configure the python bootstrap
directory. This is helpful when working across multiple platforms in a
single IDE session.
There was not much benefit to avoiding the new download (and it was
broken in some Windows compatibility work) and this ensures there are
_only_ the versions we specified
Windows doesn't support symlinks, doesn't use a `bin` directory and all
pythons are called `python.exe`.
Note that this is still broken, `.\bin\python3.10.13` is missing its
.exe extension and renaming it to `.\bin\python3.10.13.exe` makes it
complain about not finding python310.dll.
A 1:1 port of the Bash script to Python for use on Windows.
Pulls some parts of #1068 but much more minimal. Avoids an additional
dependency on `requests`. Because we require `zstandard` to unzip the
distributions we unfortunately cannot be dependency free and cannot have
`bootstrap.sh` download the Python version needed to run this script
without it doing a non-trivial amount of work.
Retains the Bash script for now so you can bootstrap without Python
available. I may drop it in the future?
