Fix Codecov integration

[blakeNaccarato]

Please check that this bug hasn't been reported before

• [X] I searched here or here and couldn't find a similar issue.

Please confirm that this bug affects the latest version

• [X] This bug affects version 2024.1.1 of copier_python.

Please indicate which operating system(s) you are using

• [ ] Linux
• [ ] macOS
• [ ] Windows

Expected behavior

Codecov should work

Current behaviour

It's not

Steps to reproduce

Run CI

Possible solution

There's some weirdness upstream at Codecov, too many issues to be worth linking out to just one of them. Keep an eye out for "unknown error" Codecov issues being resolved.

[blakeNaccarato]

Okay, no actually it was just me all along. I figured it out, need to propagate changes up to the template now. Basically, coverage files in the uv cache were being picked up by Codecov, so I should move the cache out like ../uv-cache. Need to restore the .codecov file, too.