LXD doesn't support ZFS 2.1, which in turn doesn't support ID-mapped mounts #1131

To restore Ubuntu 22.04 support, we should switch to btrfs I guess. Or just drop support, since no one seems to have noticed. I only saw it here: https://github.com/canonical/ollama-sdk/actions/runs/41752924202/job/126322115834. Might be fixed by #956.