Flaky test_avoid_paused_workers

[fjetter]

flaky TimeoutError in test_avoid_paused_workers

main ubu py3.8 https://github.com/dask/distributed/runs/4552302807?check_suite_focus=true

feature branch win py3.7 https://github.com/dask/distributed/runs/4537729477?check_suite_focus=true

E               asyncio.exceptions.TimeoutError: Test timeout after 30s.
E               Stack for <Task pending name='Task-91589' coro=<test_avoid_paused_workers() running at /home/runner/work/distributed/distributed/distributed/tests/test_scheduler.py:3235> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f24d877daf0>()]>> (most recent call last):
E                 File "/home/runner/work/distributed/distributed/distributed/tests/test_scheduler.py", line 3235, in test_avoid_paused_workers
E                   await asyncio.sleep(0.01)