events: all_tasks is now part of asyncio

[abpostelnicu]

Running the events loop causes this error:

[ERROR   ] libmozevent.utils: Failure while running async tasks (error="Error while reading from ec2-34-193-21-24.compute-1.amazonaws.com:30059 : (104, 'Connection reset by peer')")

Traceback (most recent call last):

  File "/usr/local/bin/code-review-events", line 33, in <module>

    sys.exit(load_entry_point('code-review-events==1.4.6', 'console_scripts', 'code-review-events')())

  File "/usr/local/lib/python3.9/site-packages/code_review_events-1.4.6-py3.9.egg/code_review_events/cli.py", line 78, in main

    events.run()

  File "/usr/local/lib/python3.9/site-packages/code_review_events-1.4.6-py3.9.egg/code_review_events/workflow.py", line 564, in run

    run_tasks(asyncio.Task.all_tasks())

AttributeError: type object '_asyncio.Task' has no attribute 'all_tasks'