A plea not to use uv-build for Python

@mgorny@treehouse.systems:

After seeing yet another dozen packages lose keywords on Gentoo because of a single key dependency switching to uv-build, I would like to plea on behalf of Gentoo users: please don’t use uv-build as a build backend.

Just to be clear, this is not about uv itself or any other Astral tools; these are good tools with a nice and responsive upstream. The uv-build backend is one thing we have to disagree on. I’m not saying it’s bad; I’m saying that its benefits don’t outweigh the drawbacks.