Fix codecov CI

[elringus]

At some point (probably due to a game-ci/unity-test-runner or codecov/codecov-action action update) codecov no longer uploads the coverage report: https://github.com/Elringus/SpriteDicing/runs/8296569635

I've spotted that game-ci/unity-test-runner action started ignoring -coverageResultsPath setting and now write the reports to /github/workspace/CodeCoverage; I've tried changing project root for codecov/codecov-action to that directory, but it didn't help.

If anyone have any idea on how to fix this, please let us know here.