update prune cli to start scheduler but not all of the workers

cmd/gotosocial/action/admin/media/prune/common.go

@@ -44,7 +44,10 @@ func setupPrune(ctx context.Context) (*prune, error) {
 	state.Caches.Init()
 	state.Caches.Start()
 
-	state.Workers.Start()
+	// Scheduler is required for the
+	// claner, but no other workers
+	// are needed for this CLI action.
+	state.Workers.StartScheduler()
 
 	dbService, err := bundb.NewBunDBService(ctx, &state)
 	if err != nil {