type(feat): Allow parsing of wheel file paths in requirements.in

[stridge-cruxml]

I have a .whl file inside my bazel repo. I would like to add this to requirements.in like

path/to/my.whl

Adding extra_data to pip_compile and passing this through is sufficient.
eg

compile_pip_requirements(
  ...
  extra_data = ["//path/to:my.whl"],
)

An issue I came across is pip tools puts the absolute path to the wheel in requirements.txt which isn't great.
So I change the path back to a relative one in dependency_resolver.py

Currenty you need to add labels for install_deps.

install_deps(whl_files = {"pip_my" : Label("//path/to/my.whl")})

Is there a better way to do this?

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[aignas]

Yeah I think this is as good as we can get here.

If you would like to also add the wiring for bzlmod (e.g. wire pip.override to the whl_library whl_name attribute), then I'd be happy to merge this approach. After all we are planning to release 1.0 at some point soon and bzlmod is a first class citizen.

[stridge-cruxml]

I fixed the indentation.

I am not going to dedicate more time to this for a while due to other priorities. Existing code I have all uses WORKSPACE still. If there is someone else who would be willing to implement the bzlmod side of things they are most welcome.

[aignas]

#1689 is the ticket that this PR would fix.