Depreciation warning Pydantic model_fields attribute to be deperciated. Used in compat.py.

[wj3171868]

I started getting a depreciation warnings with a recent version of Pydantic.

xsdata_pydantic/compat.py:97: PydanticDepreciatedSince211: Accessing the 'model_fields' attribute on the instance is depreciated. Instead, you should access this attribute from the model class. Depreciated in Pydantic V2.11 to be removed in V3.0

for name, info in obj.model_fields.items()

[wj3171868]

I realize this is handled here: #43