ubuntu: Enable express install for 18.10 and 21.10
With these changes, Ubuntu Express Install worked for me with GNOME Boxes 42 for Ubuntu 18.04 LTS (already enabled), 19.04 (already enabled), 18.10, 21.10, and the current daily 22.04.
For other releases, I ran into https://gitlab.gnome.org/GNOME/gnome-boxes/-/issues/779
Sorry, I had to delete my fork to fix the CI so the previous discussion is at !426 (closed)
Edited by Jeremy Bicha