tests: add test with python feature and sidecar usage

[linear]

Add a test to the CI that runs only when using the python feature using sidecars and p2p model sharing to check the rank broadcast works as expected. For this we also need to set up our self hosted runner with more than one GPU and enough memory to build all the Python related packages.

[IAvecilla]

Things left for this:

• We need to install the github cli tool in our self hosted server since it's used in one of our actions that checks that some jobs on the garnix ci has finished, sudo apt install gh should do it.
• We need to set up the repo to avoid running the CI on external contributions and wait for approval of someone on the team to actually run it.
• We need to add the services on our server to run everyday cleaning the docker images and the nix cache to avoid that growing indefinitely. These are the ones that should be set up:
  on: /etc/systemd/system/cleanup.service

[Unit]
Description=Clear all Docker-related caches
After=docker.service
Requires=docker.service

[Service]
Type=oneshot
ExecStart=/bin/sh -c "\
    docker container prune -f; \
    docker image prune -a -f; \
    docker volume prune -f; \
    docker builder prune -a -f; \
    docker volume rm $(docker volume ls -qf dangling=true); \
    nix-collect-garbage"
Nice=19
IOSchedulingClass=idle

[Install]
WantedBy=multi-user.target

on: /etc/systemd/system/cleanup.timer

[Unit]
Description=Run Docker and Nix cache cleanup everyday

[Timer]
OnCalendar=*-*-* 22:00
Persistent=false
Unit=cleanup.service

[Install]
WantedBy=timers.target