Read-only `src_dict` dictionary in `from_dict` methods should be typed as `Mapping[str, Any]`

[edgarrmondragon]

Describe the bug

Generated classmethod from_dict

openapi-python-client/openapi_python_client/templates/model.py.jinja

Lines 131 to 132 in 5cfe4e1

	@classmethod
	def from_dict(cls: type[T], src_dict: dict[str, Any]) -> T:

should probably be annotated as

    @classmethod
    def from_dict(cls: type[T], src_dict: Mapping[str, Any]) -> T:

i.e. using typing.Mapping.

This marks the input dictionary as immutable and thus mypy is OK if you pass it a TypedDict. Otherwise, it correctly complains about type-incompatibility because the method could be removing or adding keys from the dictionary.

OpenAPI Spec File

NA.

Additional context

• TypedDict -> dict compatibility python/mypy#13122 (comment)