🚀 feature request

Relevant Rules

pip_install
https://github.com/bazelbuild/rules_python/blob/aa27a3fe7e1a6c73028effe1c78e87d2e7fab641/python/pip.bzl#L19-L57

Description

Currently, any change to a requirements fill will force Bazel to download all dependencies before being able to begin a build. This can end up consuming a lot of time and feel pretty frustrating when the change to the requirements file is not relevant to what you're working on in a given project. Support should be added for incrementally fetching pip packages and only fetching dependencies required for the targets being built/tested/ran.

Describe the solution you'd like

I have found com_github_ali5h_rules_pip to be incredibly helpful for this and feel it's awesome enough to be up-streamed. If @ali5h is ok with it, then I think this would be the most effective path forward.

Describe alternatives you've considered

Alternatively, users can use com_github_ali5h_rules_pip directly or others can propose an alternative solution.