fix: switch to default-flatpaks@v2 syntax

recipes/recipe.yml

@@ -30,15 +30,14 @@ modules:
       - firefox-langpacks # also remove firefox dependency (not required for all packages, this is a special case)
 
   - type: default-flatpaks
-    notify: true # Send notification after install/uninstall is finished (true/false)
-    system:
-      # If no repo information is specified, Flathub will be used by default
-      install:
-        - org.mozilla.firefox
-        - org.gnome.Loupe
-      remove:
-        - org.gnome.eog
-    user: {} # Also add Flathub user repo, but no user packages
+    configurations:
+      - notify: true # Send notification after install/uninstall is finished (true/false)
+        scope: system
+        # If no repo information is specified, Flathub will be used by default
+        install: # system flatpaks we want all users to have and not remove
+          - org.mozilla.firefox
+          - org.gnome.Loupe
+      - scope: user # Also add Flathub user repo, but no user packages
 
   - type: signing # this sets up the proper policy & signing files for signed images to work fully