Add a `uv self update` command

[charliermarsh]

Summary

Powered by Axo: https://github.com/axodotdev/axoupdater.

Closes https://github.com/astral-sh/uv/issues/1591.

Test Plan

To test locally:

• rm -f ~/.config/uv/uv-receipt.json /Users/crmarsh/.cargo/bin/uv
• curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/uv/releases/download/0.1.14/uv-installer.sh | sh
• cargo run self update

Up-to-date:

Updated:

No receipt:

[konstin]

Found an upstream bug: https://github.com/axodotdev/axoupdater/issues/34

[charliermarsh]

We may want to consider waiting for https://github.com/axodotdev/axoupdater/issues/34, and we definitely need to wait for axoupdater to give us the updated version back (since the current messages are incorrect).

[konstin]

Thinking about https://github.com/axodotdev/axoupdater/issues/34 again, should we feature gate the installer, so that pip/conda/distros can turn it off entirely? Seem safer than relying on recipe.

[mistydemeo]

I've shipped a new version of axoupdater with a fix for axodotdev/axoupdater#34, but providing a way to turn off the self update feature entirely for certain distributions isn't a bad idea either.

[charliermarsh]

One challenge we'd have there is that we build the standalone binaries as a side-effect of the PyPI wheels. So we'd need to do separate builds (which is doable).