tests(packer): add lxqt test image, update xfce.

tests/cloud-init/archlinux-xfce.user-data.yml

@@ -1,40 +1,6 @@
 #cloud-config
 
-packages:
-  # Install core packages
-  - apparmor
-  - base-devel
-  - qemu-guest-agent
-  - rng-tools
-  - spice-vdagent
-
-  # Install usefull core packages
-  - bash-completion
-  - git
-  - just
-  - htop
-  - man
-  - pass
-  - python-notify2
-  - vim
-  - wget
-
-  # Install basic services
-  - networkmanager
-  - cups
-  - cups-pdf
-  - system-config-printer
-
-  # Install Applications
-  - firefox
-  - chromium
-  - terminator
-
-  # Install Graphical Interface
-  - xfce4
-  - xfce4-goodies
-  - lightdm
-  - lightdm-gtk-greeter
+packages: *xfce-packages
 
 runcmd:
   # Regenerate grub.cfg