- use Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcherInterface;
+ use Symfony\Contracts\EventDispatcher\EventDispatcherInterface as ContractsEventDispatcherInterface;

//...

-   if (!interface_exists(TraceableEventDispatcherInterface::class)) {
+   if ($dispatcher instanceof ContractsEventDispatcherInterface) {
        $dispatcher->dispatch($eventObject, $eventType);
    } else {
        $dispatcher->dispatch($eventType, $eventObject);
    }