Python 3.11 gets error "module ' asyncio' has no attribute 'coroutine'"

[srh]

Basically, generator-based coroutines with @asyncio.coroutine have been removed in 3.11.

https://docs.python.org/3.10/library/asyncio-task.html#generator-based-coroutines

It's unclear if this affects all users.

Apparently async def was added in Python 3.5. I don't know if a fix for 3.11 will break compatibility for older Python users.

https://docs.python.org/3.10/reference/compound_stmts.html#async-def

[srh]

Dupe of #294.