Fix shutdown being delayed for cancelling tasks

[bdraco]

Breaking change

Home Assistant will no longer wait for cancelling tasks at shutdown when running with cpython 3.11 or later.

Proposed change

cpython 3.11 introduced the concept of cancelling
https://docs.python.org/3/library/asyncio-task.html#asyncio.Task.cancelling

Once a task is being cancelled we should no longer block waiting for it since we can end up waiting multiple minutes for a long polling http request, udp discovery, etc that has already received cancellation but cancellation has not fully propagated to full stack. This is common with anyio since it won't finish the cancellation until the timeout expires.

Fixes

2023-05-19 18:52:49.856 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='c200 background pull messages' coro=<PullPointManager._async_pull_messages() running at /usr/src/homeassistant/homeassistant/components/onvif/event.py:354> wait_for=<Future cancelled> cb=[set.remove(), set.remove()]>
2023-05-19 18:52:49.858 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='HD-IPC background pull messages' coro=<PullPointManager._async_pull_messages() running at /usr/src/homeassistant/homeassistant/components/onvif/event.py:354> wait_for=<Future cancelled> cb=[set.remove(), set.remove()]>
2023-05-19 18:52:49.859 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='e1 reolink background pull messages' coro=<PullPointManager._async_pull_messages() running at /usr/src/homeassistant/homeassistant/components/onvif/event.py:354> wait_for=<Future cancelled> cb=[set.remove(), set.remove()]>
2023-05-19 18:52:49.860 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='Amcrest background pull messages' coro=<PullPointManager._async_pull_messages() running at /usr/src/homeassistant/homeassistant/components/onvif/event.py:354> wait_for=<Future cancelled> cb=[set.remove(), set.remove()]>
2023-05-19 18:52:49.860 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='LC background pull messages' coro=<PullPointManager._async_pull_messages() running at /usr/src/homeassistant/homeassistant/components/onvif/event.py:354> wait_for=<Future cancelled> cb=[set.remove(), set.remove()]>
2023-05-19 18:52:49.861 WARNING (MainThread) [homeassistant.core] Shutdown stage 0: still running: <Task cancelling name='flux_led-discovery' coro=<async_setup.<locals>._async_discovery() running at /usr/src/homeassistant/homeassistant/components/flux_led/__init__.py:97> wait_for=<_GatheringFuture pending cb=[Task.task_wakeup()]> cb=[set.remove(), set.remove()]>

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
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• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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[frenck]

LGTM, thanks, @bdraco 👍

../Frenck

[bdraco]

thanks