Resolve "Python 3.12 support"

Closes #553 (closed)

The reason of falling test is our implementation of Asyncio executor, which is using the functionally, deprecated since Py 3.8. We already had a problem with Pyhton 3.11 after _coroutine method was removed. We bypassed it by coping if its code. In Python 3.12 the cleaning-up continued and now all our methods, wrapped with _coroutine, are not allowed for execution anymore, since the coroutines.iscoroutine methods now return False for types.GeneratorType. As the result, the run_coroutine_threadsafe raises TypeError.

As an ugly and incorrect solution, we can do another round: we can again copy method code and modify it in a way, that types.GeneratorType are allowed. This work, as least pipeline pass, but I am not sure, that we test all possible scenarios.

Anyway it is definitely agony, and I am 100% sure, that this is dead end. If we are not going to finally copy the whole asyncio module, we should completely rewrite asyncio part. But it will take time.