ci: cache pre-commit deps in runners
Rather than creating a single docker image reused by all users that need to be manually updated in case a pre-commit dependency changes, cache pre-commit dependencies in each runner.
Fix #460 (closed)
This is an alternative approach to address #460 (closed):
- In
main
thechecks
image installs pre-commit and the pre-commit hooks' dependencies. - In this branch the
checks
images install pre-commit and the pre-commit hooks's dependencies are installed and cached per-runner.