fix weird pydantic litellm warnings

[antonkulaga]

BerriAI/litellm#11759

test/test_judge.py::test_question_with_judge[Q10]
  /home/antonkulaga/sources/opengenes-mcp/.venv/lib/python3.10/site-packages/pydantic/main.py:463: UserWarning: Pydantic serializer warnings:
    PydanticSerializationUnexpectedValue(Expected 9 fields but got 5: Expected `Message` - serialized value may not be as expected [input_value=Message(content='The foll...er_specific_fields=None), input_type=Message])
    PydanticSerializationUnexpectedValue(Expected `StreamingChoices` - serialized value may not be as expected [input_value=Choices(finish_reason='st...r_specific_fields=None)), input_type=Choices])
    return self.__pydantic_serializer__.to_python(