Docs: Updaing 'JSON Schema' code block output (#28909)

Out seems outdate, I ran the example several times and this is the
updated output, one key-value pair was missing!

![image](https://github.com/user-attachments/assets/95231ce7-714e-43ac-b07e-57debded4735)

Author: ahmadelmalah

docs/docs/how_to/structured_output.ipynb

@@ -206,9 +206,10 @@
     {
      "data": {
       "text/plain": [
-       "{'setup': 'Why was the cat sitting on the computer?',\n",
-       " 'punchline': 'Because it wanted to keep an eye on the mouse!'}"
-      ]
+        "{'setup': 'Why was the cat sitting on the computer?',\n",
+        " 'punchline': 'Because it wanted to keep an eye on the mouse!',\n",
+        " 'rating': 7}"
+       ]
      },
      "execution_count": 4,
      "metadata": {},