Mute asyncio warning for Serve (#11682)

python/ray/serve/__init__.py

@@ -1,6 +1,11 @@
 from ray.serve.api import (accept_batch, Client, connect, start)  # noqa: F401
 from ray.serve.config import BackendConfig
 
+# Mute the warning because Serve sometimes intentionally calls
+# ray.get inside async actors.
+import ray.worker
+ray.worker.blocking_get_inside_async_warned = True
+
 __all__ = [
     "accept_batch",
     "BackendConfig",