MDL-81525 coer_enrol: Use stoppable trait for consistency

enrol/classes/hook/before_enrol_instance_deleted.php

@@ -29,11 +29,9 @@ use Psr\EventDispatcher\StoppableEventInterface;
 #[\core\attribute\label('Allows plugins or features to perform actions before the enrolment instance is deleted.')]
 #[\core\attribute\tags('enrol', 'user')]
 class before_enrol_instance_deleted implements
-    StoppableEventInterface {
-    /**
-     * @var bool Whether the propagation of this event has been stopped.
-     */
-    protected bool $stopped = false;
+    StoppableEventInterface
+{
+    use \core\hook\stoppable_trait;
 
     /**
      * Constructor for the hook.
@@ -45,15 +43,4 @@ class before_enrol_instance_deleted implements
         public readonly stdClass $enrolinstance,
     ) {
     }
-
-    public function isPropagationStopped(): bool {
-        return $this->stopped;
-    }
-
-    /**
-     * Stop the propagation of this event.
-     */
-    public function stop(): void {
-        $this->stopped = true;
-    }
 }