refs https://github.com/actions/runner-images/issues/6002
- Ubuntu 18.04 is now deprecated in GHA
- this commit moves all tests onto 22.04 except the Admin integration
tests because they're failing to pick Firefox up
- I can look into this after we've unblocked CI
fixes https://github.com/TryGhost/Toolbox/issues/285
- without this, some of the workflows that are only useful for the core
team will run on forks
- this commit adds checks to ensure we're running on a repo maintained
by the TryGhost organization for a handful of workflows
no issue
- Renovate will open PRs to bump dependencies but these are unassigned
- Renovate does have the ability to set assignees, but these are blanket
assigns not based upon the package that is being upgraded
- we want to assign them to the owners of the package that is being
upgraded
- I've created the `gh-auto-assign` GitHub CLI exntension which reads a
`.github/AUTO_ASSIGN` file and assign PRs based upon the entries listed
- this commit adds the initial `AUTO_ASSIGN` file and GitHub Actions
workflow to trigger when a PR is opened
