Have mirrors of all external repos

This would include git repos and tarballs

This would avoid problems of upstream rate limit us when we do too many request (see #394 (closed) ), and in general is nice to not DDoS our upstreams.

Also It will allow us to be able to build even if some of the upstreams goes away for some reason

Update 15/11/2021:

• Infrastructure ansible MR to setup the service: Infrastructure/ansible!1 (merged)
• Mirrors can be configured here: https://gitlab.gnome.org/Infrastructure/Mirrors/mirroring-config