Prevent PydanticUserError in ApiClient.send for void endpoints (#90) (#94)

* Prevent PydanticUserError when ApiClient.send has no return type

Short-circuit and return None before constructing TypeAdapter when
type_ is None (e.g. 204 No Content endpoints). TypeAdapter(None) raises
PydanticUserError, and returning None matches the existing overloads.

Closes #90

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* Accept 204 No Content in ApiClient.send

Add 204 to the success status codes and short-circuit to None for it
so void endpoints stop raising UnexpectedResponse.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: oxesoft

scripts/datamodel_generate_client.py

@@ -802,13 +802,15 @@ def request_sync(self, *, type_: Any, **kwargs: Any) -> Any:
 
     async def send(self, request: Request, type_: Type[T]) -> T | str:
         response = await self.middleware(request, self.send_inner)
-        if response.status_code in [200, 201]:
+        if response.status_code in [200, 201, 204]:
             try:
                 # Use Pydantic v2 TypeAdapter for validation
+                if type_ is None or response.status_code == 204:
+                    return None
                 adapter = TypeAdapter(type_)
                 if type_ == bytes:
                     return adapter.validate_python(response.content)
-                return adapter.validate_python(response.json()) if type_ else response.text
+                return adapter.validate_python(response.json())
             except Exception as e:
                 raise ResponseHandlingException(e)
         raise UnexpectedResponse.for_response(response)