ref(roles): All roles use desired package state

By setting the `desired_package_state` variable we can change if ansible
should only ensure that the packages exist on the system (`present`) or
that they are also updated to their latest version (`latest`).

roles/packages/tasks/main.yaml

@@ -1,4 +1,4 @@
 - name: Install all my used void packages
   community.general.xbps:
     name: "{{ lookup('community.general.merge_variables', '^packages_.*') }}"
-    state: "{{ desired_package_state }}"
+    state: "{{ desired_package_state | default('present') }}"