code: public static void removeLegacySubscriptionOnParent(ExecutionEntity execution, EventSubscriptionEntity eventSubscription) {
      ActivityImpl activity = execution.getActivity();
      if (activity == null) {
        return;
      }
  
      ActivityBehavior behavior = activity.getActivityBehavior();
      ActivityBehavior parentBehavior = (ActivityBehavior) (activity.getFlowScope() != null ? activity.getFlowScope().getActivityBehavior() : null);
  
      if (behavior instanceof ReceiveTaskActivityBehavior &&
          parentBehavior instanceof MultiInstanceActivityBehavior) {
        List<EventSubscriptionEntity> parentSubscriptions = execution.getParent().getEventSubscriptions();
  
        for (EventSubscriptionEntity subscription : parentSubscriptions) {
          // distinguish a boundary event on the mi body with the same message name from the receive task subscription
          if (areEqualEventSubscriptions(subscription, eventSubscription)) {
            subscription.delete();
          }
        }
      }
  
    }
docs: <p>Required for migrating active sequential MI receive tasks. These activities were formerly not scope,
  but are now. This has the following implications:
  
  <p>Before migration:
  <ul><li> the event subscription is attached to the miBody scope execution</ul>
  
  <p>After migration:
  <ul><li> a new subscription is created for every instance
  <li> the new subscription is attached to a dedicated scope execution as a child of the miBody scope
  execution</ul>
  
  <p>Thus, this method removes the subscription on the miBody scope