Add GitHub Actions workflow that fails if any deprecated exercise files change

[sanderploegsma]

Some exercises on this track have been deprecated and should no longer be updated.

To make sure this doesn't happen accidentally anyway, we could add a workflow to GitHub actions that checks if any of the files changed in a PR belong to a deprecated exercise and if so, fail. This action should only run on PRs.

For more information on the deprecation of exercises, see https://exercism.org/docs/building/tracks/deprecated-exercises.