code: def update_all_apps(self):
          
          for app in apps.get_app_configs():
              self.update_app(app.name)
  
          # During update_app, all apps added model objects that were registered for deletion.
          # Delete all objects that were previously managed by the initial data process
          self.handle_deletions()
docs: Loops through all app names contained in settings.INSTALLED_APPS and calls `update_app`
          on each one. Handles any object deletions that happened after all apps have been initialized.