[BUG] [PYTHON] Generated Python code fails to deserialize dictionary objects

Description

Generated Python code fails to deserialize dictionary objects

openapi-generator version

7.5.0

OpenAPI declaration file content or url

see this repo for complete example and explanation.

Generation Details

Problem is probably caused by the code to deserialize a dict:

    @classmethod
    def from_dict(cls, obj: Dict) -> Self:
        """Create an instance of User from a dict"""
        if obj is None:
            return None

        # Why don't we just let handle pydantic the deserialization? The generated code completely ignores the relations 
        # attribute.
        # 
        # This code works for me
        #  _obj = cls.model_validate(obj)
        # return _obj
        # 
        # The generated code below does not
        if not isinstance(obj, dict):
            return cls.model_validate(obj)

        _obj = cls.model_validate({
            "name": obj.get("name"),
            "address": Address.from_dict(obj.get("address")) if obj.get("address") is not None else None,
        })
        return _obj

Steps to reproduce

Checkout this repo
pip install -r requirements.txt
uvicorn main:app --reload
python client.py

Related issues/PRs

Suggest a fix

Start with the linked reproduction repository, install requirements.txt, run uvicorn main:app --reload, and execute client.py. Inspect the generated Python model's from_dict path and compare its handling of dictionary objects and the relations attribute with the reproduction's expected behavior; done means the client deserializes the example successfully.