fix(examples): update client usage to prefer await aclose() in async context" (#2839)

examples/client/flow_crud_example.py

@@ -37,8 +37,12 @@ async def main():
     # initialize client
     DBGPT_API_KEY = "dbgpt"
     client = Client(api_key=DBGPT_API_KEY)
-    res = await list_flow(client)
-    print(res)
+    try:
+        res = await list_flow(client)
+        print(res)
+    finally:
+        # explicitly close client to avoid event loop closed error
+        await client.aclose()
 
 
 if __name__ == "__main__":