Sanic ASGI warning when running as prescribed by docs

[JamesHutchison]

The docs currently recommend running via Sanic directly.

https://reactpy.dev/docs/guides/getting-started/running-reactpy.html#running-with-sanic

However, if you do, you get this warning:

No scope. Sanic may not be running with an ASGI server

It seems like if users should be using the built-in Sanic server then this warning should be remove, as it is emitted by ReactPy here:

https://github.com/reactive-python/reactpy/blob/main/src/py/reactpy/reactpy/backend/sanic.py#L167

If users should be using ASGI to serve Sanic, then instructions on how to do that should be provided.

[zx013]

I got this too, it seems not effect reactpy work.