Also updates CI pypy versions to be 3.9 and 3.10 which are the currently
[supported
versions](https://www.pypy.org/posts/2024/01/pypy-v7315-release.html).
Otherwise latest cryptography doesn't ship with pypy3.8 wheels and is
unable to build on windows.
Also updates the `codecov-action` to v4 which fixed some intermittent
uploading errors.
Adds auto-off implementation. The feature stays enabled after the timer runs out, and it will start the countdown if the device is turned on again without explicitly disabling it.
New features:
* Switch to select if enabled: `Auto off enabled (auto_off_enabled): False`
* Setting to change the delay: `Auto off minutes (auto_off_minutes): 222`
* If timer is active, datetime object when the device gets turned off: `Auto off at (auto_off_at): None`