Ensure that our org uses shared workflows from openedx, not edx

[kdmccormick]

Context

• This .github repo was copied from https://github.com/edx/.github
• Shared workflows (in ./.github/workflows) exist in both this repo and in the edx version of this repo.
• Our repositories should reference the openedx version of the shared workflows, but we still reference the edx version of the workflow in many places: https://github.com/search?q=%22edx%2F.github%2F.github%2Fworkflows%2Fcommitlint%22+org%3Aopenedx&type=code
• A lot of progress was made over here: Audit and fix edx vs openedx workflows and templates #2. This ticket is follow-up.

Acceptance Criteria

• For every repo in the openedx org:
  • For every GitHub Action workflow in the repo:
    • Ensure that any and all shared workflow references point to the openedx organization, not the edx organization.

Examples

What we want: https://github.com/openedx/acid-block/blob/1f76d2860013cb2e046bb1659c5c74b76775b50c/.github/workflows/commitlint.yml#L10

What we don't want: https://github.com/openedx/api-doc-tools/blob/81edb71fd132a66280be3af822c88e224bfb4f83/.github/workflows/commitlint.yml#L10

Notes

GitHub search can be used to find offending examples, e.g.: https://github.com/search?q=%22edx%2F.github%2F.github%2Fworkflows%2Fcommitlint%22+org%3Aopenedx&type=code

If we want to automate this, we could use @feanil 's new repo checks framework. Specifically, we add a Check subclass that:

• in the is_relevant(...) method, returned True;
• in the check(...) method, searched for the substring "uses: edx/" within all YAML files in the .github directory;
• in the fix(...) method, opened a PR to replace "uses: edx/" with "uses: openedx/".