Attribute background migrations to database category

app/workers/all_queues.yml

@@ -907,7 +907,7 @@
   :weight: 2
   :idempotent: true
 - :name: background_migration
-  :feature_category: :not_owned
+  :feature_category: :database
   :has_external_dependencies: 
   :urgency: :low
   :resource_boundary: :unknown

app/workers/background_migration_worker.rb

@@ -3,7 +3,7 @@
 class BackgroundMigrationWorker # rubocop:disable Scalability/IdempotentWorker
   include ApplicationWorker
 
-  feature_category_not_owned!
+  feature_category :database
 
   # The minimum amount of time between processing two jobs of the same migration
   # class.