gitlab-rulez: Use git to fetch the rules with CI_JOB_TOKEN
GitLab does not currently grant access to the raw files API endpoints to
CI_JOB_TOKEN
in any way. However, it allows for CI_JOB_TOKEN
to be used
to clone via git
so let's use that until the situation improves:
https://gitlab.com/gitlab-org/gitlab/-/issues/424161