fix pattern_async_actor demo

Signed-off-by: curiosity-hyf <[email protected]>

Author: curiosity-hyf

doc/source/ray-core/doc_code/pattern_async_actor.py

@@ -51,7 +51,7 @@ async def run(self):
             # Here we use await instead of ray.get() to
             # wait for the next task and it will yield
             # the control while waiting.
-            task = await task_store.get_next_task.remote()
+            task = await self.task_store.get_next_task.remote()
             self._execute_task(task)
 
     def _execute_task(self, task):