Update career_conversations app

Pract_Lab1.ipynb

@@ -179,7 +179,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 1,
    "id": "c644660b",
    "metadata": {},
    "outputs": [],

app.py

@@ -193,7 +193,7 @@ If the user is engaging in discussion, try to steer them towards getting in touc
                     message_obj = response.choices[0].message
                     tool_calls = message_obj.tool_calls
                     results = self.handle_tool_call(tool_calls)
-                    messages.append(message_obj)
+                    messages.append(message_obj.model_dump())
                     messages.extend(results)
                 else:
                     done = True