[5.7] Update docblock on Job contract's "release" method (#25998)

* update docblock on InteractsWithQueue::release()

Fixes #25915

* Update InteractsWithQueue.php

* update Job contract "release" docblock

src/Illuminate/Contracts/Queue/Job.php

@@ -29,7 +29,7 @@ public function fire();
      * Release the job back into the queue.
      *
      * @param  int   $delay
-     * @return mixed
+     * @return void
      */
     public function release($delay = 0);