[Serve][Doc] Fix object detection code to use gpu device (ray-project…

…#42069)

Signed-off-by: Sihan Wang <sihanwang41@gmail.com>

doc/source/serve/doc_code/object_detection.py

@@ -17,7 +17,7 @@
 @serve.ingress(app)
 class APIIngress:
     def __init__(self, object_detection_handle: DeploymentHandle):
-        self.handle = object_detection_handle
+        self.handle = object_detection_handle.options(use_new_handle_api=True)
 
     @app.get(
         "/detect",
@@ -39,6 +39,7 @@ class ObjectDetection:
     def __init__(self):
         self.model = torch.hub.load("ultralytics/yolov5", "yolov5s")
         self.model.cuda()
+        self.model.to(torch.device(0))
 
     def detect(self, image_url: str):
         result_im = self.model(image_url)