Fix flaky test_resources_reset_after_cancelled_task

[crusaderky]

Fix race condition when future.cancel() travels slower from client to scheduler than lock.release travels from client to scheduler to worker.

https://github.com/dask/distributed/pull/8367/checks?check_run_id=19069185771

        await future.cancel()
        await lock.release()
    
        while w.state.executing_count:
            await asyncio.sleep(0.01)
    
>       assert not s.workers[w.address].used_resources["A"]
E       assert not 1

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

       27 files  ±  0         27 suites  ±0   11h 53m 44s ⏱️ + 1m 44s
  3 934 tests ±  0    3 821 ✔️ +  2     110 💤 ±0  3 ❌  - 2 
49 488 runs  +18  47 195 ✔️ +26  2 290 💤  - 6  3 ❌  - 2 

For more details on these failures, see this check.

Results for commit 2423b62. ± Comparison against base commit a7cf54f.

[milesgranger]

LGTM. 👍