fix: update OpenAI responses API tracing example to accumulate response content

Author: viniciusdsmello

examples/tracing/openai/openai_responses_api_tracing.ipynb

@@ -146,13 +146,13 @@
     "    messages=[{\"role\": \"user\", \"content\": \"Count from 1 to 3\"}],\n",
     "    stream=True\n",
     ")\n",
+    "response = ''\n",
     "\n",
     "# Consume the stream - automatically traced\n",
     "for chunk in stream:\n",
     "    if chunk.choices[0].delta.content:\n",
-    "        pass  # Process chunks as needed\n",
-    "\n",
-    "# ✓ All requests automatically traced to Openlayer!"
+    "        response += chunk.choices[0].delta.content\n",
+    "response"
    ]
   },
   {