Migrate to XDG and Linux strategy for macOS directories (#5806)
This PR moves us to the Linux strategy for our global directories on
macOS. We both feel on the team _and_ have received feedback (in Issues
and Polls) that the `Application Support` directories are more intended
for GUIs, and CLI tools are correct to respect the XDG variables and use
the same directory paths on Linux and macOS.
Namely, we now use:
- `/Users/crmarsh/.local/share/uv/tools` (for tools)
- `/Users/crmarsh/.local/share/uv/python` (for Pythons)
- `/Users/crmarsh/.cache/uv` (for the cache)
The strategy is such that if the `/Users/crmarsh/Library/Application
Support/uv` already exists, we keep using it -- same goes for
`/Users/crmarsh/Library/Caches/uv`, so **it's entirely backwards
compatible**.
If you want to force a migration to the new schema, you can run:
- `uv cache clean`
- `uv tool uninstall --all`
- `uv python uninstall --all`
Which will clean up the macOS-specific directories, paving the way for
the above paths. In other words, once you run those commands, subsequent
`uv` operations will automatically use the `~/.cache` and `~/.local`
variants.
Closes https://github.com/astral-sh/uv/issues/4411.
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Co-authored-by: Zanie Blue <contact@zanie.dev>