feat(manager/pip-compile): Allow paths relative to repository root

[not7cd]

Changes

pip-compile manager should be able to extract lock files in any location within the repository. It will also extract package files from proper locations, relative to a working directory. It achieves this by inferring the working directory where the command was executed from. As all files are found relative to this repository.

Context

Minimal reproduction repository: https://github.com/icetek-lab/renovate-case1/

Documentation (please check one with an [x])

• [ ] I have updated the documentation, or
• [ ] No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• [ ] Code inspection only, or
• [ ] Newly added/modified unit tests, or
• [ ] No unit tests but ran on a real repository, or
• [x] Both unit tests + ran on a real repository

[not7cd]

I'm unable to check for local path for detected package files

[not7cd]

I'm flabbergasted by the fact that I can't use isValidPath but can ensurePath. Even though their implementation looks the same. I don't have sanity to check this further, so try...catch stays.

[renovate-release]

:tada: This PR is included in version 37.203.0 :tada:

The release is available on:

• GitHub release
• npm package (@latest dist-tag)
• 37.203.0

Your semantic-release bot :package::rocket: