Create workflow that lints shared workflows on PRs

[cheyer]

🚀 Feature Description

We recently had a change in the .github workflows that are shared across the repositories which led to all pipelines being broken. The error was (dotstudio example):

Caution

Invalid workflow file: .github/workflows/manage-pr.yml#L120
The workflow is not valid. dot-base/.github/.github/workflows/merge-release-pr.yml@main (Line: 120, Col: 11): Secret GH_BOT_PAT is required, but not provided while calling.

We can fix this by adding GH action PR workflows for this repo to, as in all other repos.

The workflow that is triggered for PRs here should invoke the manage-pr.yml workflow. This will ensure, that Github itself is parsing the manage-pr.yml workflow and all referenced other workflows.

Maybe we can customize the code-check step to include workflow linters, e.g.:

• https://github.com/rhysd/actionlint
• https://github.com/mpalmer/action-validator
• etc.

✔ Acceptance Criteria

• Add workflow that is triggered by PRs and uses manage-pr.yml
• Customize code-check step to also handle linting for workflows
• [Optional]: add workflow linting locally (add to Readme)
• Make the check mandatory for merging (branch protection rules)