Create loop in get_event_loop if needed

[zvyn]

This fixes issue #702.

[ypnos]

This behavior is deprecated since Python 3.13: https://docs.python.org/3.13/library/asyncio-eventloop.html#asyncio.get_event_loop

[zvyn]

This behavior is deprecated since Python 3.13: https://docs.python.org/3.13/library/asyncio-eventloop.html#asyncio.get_event_loop

Thanks for pointing that out @ypnos, I changed the PR to follow the asyncio behavior more closely.