Ignore missing stubs import of grpc.aio

Required since stubs for grpc.aio are not yet available

See shabbyrobe/grpc-stubs#22 (comment)

chai/chai.py

@@ -7,9 +7,13 @@
 #
 from __future__ import annotations
 from collections.abc import Awaitable
+# TODO remove ignore when stubs are availabe for grpc.aio
+# See https://github.com/shabbyrobe/grpc-stubs/issues/22
+import grpc.aio as aio  # type: ignore
 
 from typing import Optional, TypeVar
-from grpc import ChannelConnectivity, aio
+from grpc import ChannelConnectivity
+import grpc.aio as aio
 import chai.transExplorer_pb2 as msg
 import chai.transExplorer_pb2_grpc as service
 from contextlib import asynccontextmanager