More linting fixes

Author: danielmillerp

examples/demos/procurement_agent/project/workflow.py

@@ -105,7 +105,7 @@ async def on_task_event_send(self, params: SendEventParams) -> None:
         if self._state.turn_number > 1:
             # put human message in human queue
             # Extract text content from the event
-            if hasattr(params.event.content, 'content'):
+            if isinstance(params.event.content, TextContent):
                 await self.human_queue.put(params.event.content.content)
 
             await adk.messages.create(task_id=params.task.id, content=TextContent(