desktop: drop noctalia dotfiles and inventory vars

Remove the noctalia config tree and its desktop_void_dotfiles entry,
plus the unused noctalia_bar_monitors / noctalia_screen_overrides vars.
Not used by any role.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ansible/inventory/group_vars/void.yml

@@ -130,10 +130,6 @@ desktop_void_dotfiles:
     src: .local/bin/update-turnstile-env
     dest: .local/bin/update-turnstile-env
     mode: "0755"
-  - name: Noctalia config
-    src: .config/noctalia/
-    dest: .config/noctalia/
-    mode: preserve
 
 desktop_common_packages:
   - blueman