Replace flaky Thread.sleep calls with proper synchronization:

- SharedProcessorTest: use Semaphore(0).acquire() instead of
  Thread.sleep(10s) so the worker blocks until interrupted by
  shutdownNow(), making the test deterministic and instant.

- KubernetesReconcilerCreatorTest: use Wait.poll() instead of
  Thread.sleep(500ms) to actively poll until the work queue is
  populated, making the test faster and non-flaky.

Addresses part of kubernetes-client#1223.

Co-Authored-By: Oz <oz-agent@warp.dev>

Address the remaining Thread.sleep usages from kubernetes-client#1223:

- ExecCallbacksTest: replace Thread.sleep(30s) with Semaphore(0).acquire()
  so the simulated remote process blocks until the exec timeout fires,
  making the test instant and non-flaky.

- CopyTest: replace Thread.sleep(2000) with Awaitility.await() polling
  WireMock's serve events, so we proceed as soon as the HTTP request
  is received rather than waiting a fixed 2 seconds.

- PortForwardTest: remove Thread.sleep(2000) entirely; handler.close()
  is called while the main thread holds the monitor lock, so there is
  no race condition and no need for a timed wait.

- DefaultDelayingQueueTest: remove Thread.sleep(10s) after queue.done();
  the queue uses an injected (static) time source, so no items will be
  spontaneously enqueued and the assertion can be made immediately.

- DefaultWorkQueueTest: remove Thread.sleep calls used to simulate
  producer/consumer work; the test correctness is governed by
  CountDownLatches, not by sleep timing.

- EventCorrelatorTest: replace Thread.sleep(100) with an explicit
  timestamp offset (plusMillis(100)) so event timestamps are guaranteed
  to differ without any real-time wait.

Co-Authored-By: Oz <oz-agent@warp.dev>