ollama-structured-output-fix-phi-2164 (#1547)

Changes:

- Ollama structured output fix 


![image](https://github.com/user-attachments/assets/c8c8654c-90d7-441c-848f-1084cdf747dd)

phi/model/ollama/chat.py

@@ -445,7 +445,7 @@ def response(self, messages: List[Message]) -> ModelResponse:
             ):
                 parsed_object = self.response_format.model_validate_json(response.get("message", {}).get("content", ""))
                 if parsed_object is not None:
-                    model_response.parsed = parsed_object
+                    model_response.parsed = parsed_object.model_dump_json()
         except Exception as e:
             logger.warning(f"Error parsing structured outputs: {e}")
 
@@ -508,7 +508,7 @@ async def aresponse(self, messages: List[Message]) -> ModelResponse:
             ):
                 parsed_object = self.response_format.model_validate_json(response.get("message", {}).get("content", ""))
                 if parsed_object is not None:
-                    model_response.parsed = parsed_object
+                    model_response.parsed = parsed_object.model_dump_json()
         except Exception as e:
             logger.warning(f"Error parsing structured outputs: {e}")