Add support for multiple requirements.in files

[froody]

No description provided.

[mark-thm]

Thanks — I’d prefer this functionality live outside of this ruleset, though.

[hofbi]

https://github.com/theoremlp/rules_uv/tree/main/examples/multiple-inputs is a good example how this can be solved with the existing ruleset.

[baxelrod-bdai]

I'm in favor of this feature. This fixes issue #86.

Minor nit: I'd probably make it so the requirements_in argument can take a single file or list of files rather than make the new argument requirements_ins.

[baxelrod-bdai]

Actually, this hack is a bit ugly. uv does support multiple .in files. We should just pipe the files all the way to uv instead of concatenating the files ourselves.

[shayanhoshyari]

Thanks — I’d prefer this functionality live outside of this ruleset, though.

+1. Just merge with genrule or something.