enable OSUOSL shared gitlab runners globally on Salsa

OSUOSL has setup a set of auto-scaling, ephemeral Docker GitLab Runners that run in disposible VMs, all automated by Chef. This setup was designed around the requirements as laid out by the Salsa Admins when I first discussed it in #salsa a while back. They are adding this as one of their officially supported services that they provide to trusted free software projects. F-Droid and Tor Project are currently beta testing them.

The runners are auto-scaling Docker, set to run one job per-CPU, then destroy the Docker container after each job. They manage the runner tokens in their Chef setup, so they can destroy and recreate the whole thing without bothering the GitLab admins (e.g. gitlab.torproject.org, salsa.debian.org, etc.).

These runners will provide the salsa-ci team with new architectures for better coverage of all of Debian:

arm64
s390x
ppc64le
amd64 (for more capacity on common jobs)

You can see a beta version of this setup here: https://salsa.debian.org/groups/android-tools-team/-/runners

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information