[<Ray component: Core|RLlib|etc...>] Support for Gradio version 4 on Ray Serve

[SuryaaSeran]

Description

Currently, we are facing an issue with using Gradio v4 on Ray 2.40.0 (latest version). Could you please help us with a fix to support the latest Gradio version, as many of our LLM demos require features from Gradio v4? If there are any workarounds, please do let us know. It would be great if you could update the documentation as well (https://docs.ray.io/en/latest/serve/tutorials/gradio-integration.html). I have pasted the error logs below.

The deployment failed to start 8 times in a row. This may be due to a problem with its constructor or initial health check failing. See controller logs for details. Retrying after 32.0 seconds. Error:
[36mray::ServeReplica:xyz_app:GradioUI.initialize_and_get_metadata()[39m (pid=771, ip=100.64.50.78, actor_id=1feda3fd4a666b60ece7612a01000000, repr=<ray.serve._private.replica.ServeReplica:conversational_search_app:GradioUI object at 0x7f23bdfed370>)
  File "/home/ray/anaconda3/lib/python3.8/concurrent/futures/_base.py", line 437, in result
    return self.__get_result()
  File "/home/ray/anaconda3/lib/python3.8/concurrent/futures/_base.py", line 389, in __get_result
    raise self._exception
  File "/home/ray/anaconda3/lib/python3.8/site-packages/ray/serve/_private/replica.py", line 455, in initialize_and_get_metadata
    raise RuntimeError(traceback.format_exc()) from None
RuntimeError: Traceback (most recent call last):
  File "/home/ray/anaconda3/lib/python3.8/site-packages/ray/serve/_private/replica.py", line 443, in initialize_and_get_metadata
    await self._initialize_replica()
  File "/home/ray/anaconda3/lib/python3.8/site-packages/ray/serve/_private/replica.py", line 182, in initialize_replica
    await sync_to_async(_callable.__init__)(*init_args, **init_kwargs)
  File "/tmp/ray/session_2024-12-09_15-16-36_544792_8/runtime_resources/working_dir_files/xyz/gradio_ui.py", line 57, in __init__
    submit_button.click(
  File "/tmp/ray/session_2024-12-09_15-16-36_544792_8/runtime_resources/pip/b6b53b3c285b9689fa850df780274a829a8f55a8/virtualenv/lib/python3.8/site-packages/gradio/events.py", line 550, in event_trigger
    return Dependency(block, dep.get_config(), dep_index, fn, timer)
  File "/tmp/ray/session_2024-12-09_15-16-36_544792_8/runtime_resources/pip/b6b53b3c285b9689fa850df780274a829a8f55a8/virtualenv/lib/python3.8/site-packages/gradio/blocks.py", line 581, in get_config
    "inputs": [block._id for block in self.inputs],
  File "/tmp/ray/session_2024-12-09_15-16-36_544792_8/runtime_resources/pip/b6b53b3c285b9689fa850df780274a829a8f55a8/virtualenv/lib/python3.8/site-packages/gradio/blocks.py", line 581, in <listcomp>
    "inputs": [block._id for block in self.inputs],
AttributeError: 'RunnableWithMessageHistory' object has no attribute '_id'

Use case

Please support Gradio v4 on latest Ray Serve (for LLM demos)