Fix the parallel watch. (#2182)

* Fix the parallel watch.

We should be executing the runnable here, not submitting it to the executor queue.
(This function is already running within that queue)

Co-authored-by: Scott Crosby <scrosby@twosigma.com>

scheduler/java/com/twosigma/cook/kubernetes/ParallelWatchQueue.java

@@ -97,7 +97,7 @@ void processDeque() {
                     var event = deque.removeFirst();
                     // Mark event as dequeed so we release any backpressure.
                     queueSlotsLeft.release();
-                    executor.submit(event);
+                    event.run();
                 }
             } finally {
                 lock.unlock();