[FR] Allow passing --constraints/--build-constraints to uv build

[alex]

uv build will download dependencies that are needed to build the sdist/wheel.

It'd be great if it were possible to pass --constraints/--build-constraints so we can enforce versions that are downloaded.

[alex]

One note: pip currently will enforce a hash for the input file (e.g. pip build --require-hashes -c constraints.txt my-sdist.tar.gz will require a hash for my-sdist.tar.gz). I don't find this to be the expected behavior, I'd expect the constraints to cover the downloaded files, not the local input.