Add setup instructions for DRAC (ComputeCanada) clusters

[lebrice]

• Test out Podman on Narval. Does it work with GPUs?
  • If podman works with GPUs on DRAC clusters, then try to use docker locally and Podman on the cluster, see if the devcontainers can work in this way. Ask @lebrice for some tips first, then @JesseFarebro only as needed.
• Regardless of podman or containers, add instructions for how to use either Conda + pdm or just pdm to install dependencies on Narval.
• Add a self-hosted GitHub runner to run tests on a DRAC cluster (ask @lebrice for tips)