jobs: Switch to GitLab production URLs

Switch from GitLab staging to GitLab production URLs now all jobs have been ported and tested to use GitLab instead of Phabricator.

If we land this right now, this would break some jobs that are triggered on a regular basis (like swh-docs builds) as I also updated the git clone URLs to the GitLab ones. So we should wait for GitLab production to be ready.

Depends on !123 (closed)

cc @teams/sysadmin (<- @anlambert, @vlorentz just so you know, this then appears in the todo in the upper right corner to the highlighted group/person)

Migrated from D9005 (view on Phabricator)