Clean up scheduled executor lifecycle in ProfilerGlobalCooldownTest

[Copilot]

ProfilerGlobalCooldownTest created a scheduled thread pool per test and never shut it down. Since profileAndUpload() schedules delayed work on that executor, the test could leave background tasks running and become timing-sensitive.

• Scope

  • Limit the change to ProfilerGlobalCooldownTest
  • Address the review comment without changing profiler behavior

• Executor lifecycle

  • Replace the ad hoc scheduled pool with a daemon single-thread scheduled executor
  • Track created executors in the test class
  • Shut them down in @AfterEach so no background work survives the test

• Effect

  • Prevent lingering non-daemon threads from affecting test completion
  • Reduce flakiness from scheduled work continuing past assertions

@AfterEach
void tearDown() {
  scheduledExecutorServices.forEach(ScheduledExecutorService::shutdownNow);
  scheduledExecutorServices.clear();
}

ScheduledExecutorService scheduledExecutorService =
    Executors.newSingleThreadScheduledExecutor(
        runnable -> {
          Thread thread = new Thread(runnable);
          thread.setDaemon(true);
          return thread;
        });