Push scopes out of find_registry_differences

And defer refactoring GeoNode#lfs_objects for a follow up.

ee/app/finders/geo/file_registry_finder.rb

@@ -54,8 +54,7 @@ module Geo
     #
     # @return [Array] the first element is an Array of untracked IDs, and the second element is an Array of tracked IDs that are unused
     def find_registry_differences(range)
-      source = local_storage_only? ? replicables.with_files_stored_locally : replicables
-      source_ids = source.id_in(range).pluck(replicable_primary_key) # rubocop:disable CodeReuse/ActiveRecord
+      source_ids = replicables.id_in(range).pluck(replicable_primary_key) # rubocop:disable CodeReuse/ActiveRecord
       tracked_ids = syncable.pluck_model_ids_in_range(range)
 
       untracked_ids = source_ids - tracked_ids

ee/app/finders/geo/lfs_object_registry_finder.rb

@@ -3,7 +3,9 @@
 module Geo
   class LfsObjectRegistryFinder < FileRegistryFinder
     def replicables
-      current_node(fdw: false).lfs_objects
+      lfs_objects = current_node(fdw: false).lfs_objects
+
+      local_storage_only? ? lfs_objects.with_files_stored_locally : lfs_objects
     end
 
     def syncable