We want non-DevOps to be able to deploy project documentation (ex:
repod) with GitLab Pages and a separate domain was considered the only
sensible solution due to security issues[1].
[1] https://github.blog/2013-04-09-yummy-cookies-across-domains/
roles/prometheus/defaults/main.yml used to include a comment with the
commands used to generate a list of HTTPS endpoints to check. Move it
into a proper script and fix it to generate the correct current list.