CI: Add reusable workflow to clear caches within a repository

[akihironitta]

Before submitting

• [:eyes:] Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

Adds a reusable workflow that clears caches match with the given pattern.

Usage

name: Clear cache weekly

on:
  schedule:
    # on Sundays
    - cron: "0 0 * * 0"

jobs:
  clear-cache:
    uses: Lightning-AI/utilities/.github/workflows/clear-cache.yml@v9.9.9
    with:
      pattern: 'pip|conda|docs'  # remove caches whose key includes any of the strings (`pip`, `conda`, and `docs`).

or anther example here: Lightning-AI/pytorch-lightning#14593

Motivation

I think this will be very nice as we can simplify workflows by removing the logic around weekly cache reset (like env.TIME_PERIOD) from workflow files.

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃