Why are these changes needed?

Add labels param in python ray.init() to setting node labels
user cases:

  labels = {"gpu_type": "A100", "region": "us"}
  ray.init(labels=labels)
  assert ray.nodes()[0]["Labels"] == labels
  ray.shutdown()
  ray.init(labels={})
  assert ray.nodes()[0]["Labels"] == {}

Related issue number

Enhancing node affinity scheduling feature through node labels #34894

(P1)Finalize the format for setting node labels in the ray.init() interface of Python worker.

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    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
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• Testing Strategy
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