Remove phpstan errors from integration Tasks tests

[MAILPOET-3235]

tests/integration/Tasks/SendingTest.php

@@ -92,6 +92,8 @@ class SendingTest extends \MailPoetTest {
     $this->sending->save();
     $task = ScheduledTask::findOne($this->task->id);
     $queue = SendingQueue::findOne($this->queue->id);
+    assert($task instanceof ScheduledTask);
+    assert($queue instanceof SendingQueue);
     expect($task->status)->equals($status);
     expect($queue->newsletterRenderedSubject)->equals($newsletterRenderedSubject);
   }

tests/integration/Tasks/Subscribers/BatchIteratorTest.php

@@ -47,6 +47,7 @@ class BatchIteratorTest extends \MailPoetTest {
       $i++;
 
       // process subscribers
+      // @phpstan-ignore-next-line
       ScheduledTaskSubscriber::where('task_id', $this->taskId) 
         ->whereIn('subscriber_id', $batch)
         ->findResultSet()