Issue #3364958: Stages should be destroyed in the background, during cron runs

package_manager/tests/src/Kernel/StageOwnershipTest.php

@@ -238,4 +238,5 @@ class StageOwnershipTest extends PackageManagerKernelTestBase {
     // We should be able to destroy the stage if we ignore ownership.
     $not_owned->destroy(TRUE);
   }
+
 }