tests: add debian/ubuntu based tests images.

Also some cleanup of tests resources.

tests/cloud-init/debian.yml

@@ -23,7 +23,7 @@ core-packages: &core-packages
   - unattended-upgrades
   - vim
 
-gnome-packages: &desktop-packages
+gnome-packages: &gnome-packages
   # Core packages for Debian
   - apparmor-profiles
   - apparmor-utils
@@ -53,7 +53,7 @@ gnome-packages: &desktop-packages
   - loupe
   - ptyxis
 
-kde-packages: &kubuntu-packages
+kde-packages: &kde-packages
   # Core packages for Debian
   - apparmor-profiles
   - apparmor-utils
@@ -79,6 +79,7 @@ kde-packages: &kubuntu-packages
   # KDE packages for Debian
   - spice-vdagent
   - task-kde-desktop
+  - plasma-workspace-wayland
   - terminator
 
 debian12-runcmd: &debian12-runcmd