Add ``__reduce__`` method to Exception types

Confirm this is a feature request for the Python library and not the underlying OpenAI API.

• This is a feature request for the Python library

Describe the feature or improvement you're requesting

When trying to use the openai-python library in an environment that requires pickling, like Ray, OpenAI exceptions cause failures like:

7m    "traceback: Traceback (most recent call last):",
    "  File \"/opt/conda/lib/python3.10/site-packages/ray/exceptions.py\", line 51, in from_ray_exception",
    "    return pickle.loads(ray_exception.serialized_exception)",
    "  File \"/opt/conda/lib/python3.10/site-packages/openai/_exceptions.py\", line 101, in __init__",
    "    super().__init__(message=\"Request timed out.\", request=request)",
    "TypeError: super(type, obj): obj must be an instance or subtype of type",
    "",
    "The above exception was the direct cause of the following exception:",
    "",
    "Traceback (most recent call last):",
    "  File \"/opt/conda/lib/python3.10/site-packages/ray/_private/serialization.py\", line 460, in deserialize_objects",
    "    obj = self._deserialize_object(data, metadata, object_ref)",
    "  File \"/opt/conda/lib/python3.10/site-packages/ray/_private/serialization.py\", line 342, in _deserialize_object",
    "    return RayError.from_bytes(obj)",
    "  File \"/opt/conda/lib/python3.10/site-packages/ray/exceptions.py\", line 45, in from_bytes",
    "    return RayError.from_ray_exception(ray_exception)",
    "  File \"/opt/conda/lib/python3.10/site-packages/ray/exceptions.py\", line 54, in from_ray_exception",
    "    raise RuntimeError(msg) from e",
    "RuntimeError: Failed to unpickle serialized exception",

This is because there is no __reduce__ method defined on the openai exceptions.

See Ray documentation on serialization here: https://docs.ray.io/en/latest/ray-core/objects/serialization.html#customized-serialization, im sure this would affect other runtime environments too

Can a __reduce__ method be added to exceptions so runtimes, like Ray, do not fail when there is an OpenAI exception?

Additional context

No response

Start with openai/_exceptions.py, especially the exception constructor shown at line 101, and inspect how the exception types are defined. Add coverage for pickling and unpickling the affected exceptions, then verify that reconstructed exceptions no longer fail in serialization environments such as Ray.