fix introduction_to_deep_research_api_agents.ipynb

`-alpha` version of the model dose not exist

Author: vincentkoc

examples/deep_research_api/introduction_to_deep_research_api_agents.ipynb

@@ -85,7 +85,7 @@
       "source": [
         "### Basic Deep Research Agent\n",
         "\n",
-        "The Basic Research Agent performs Deep Research using the o4-mini-deep-research-alpha model. It has native WebSearch access to the public internet and streams its findings directly back into the notebook. In this case we are using the `o4-mini-deep-research-alpha` model, because it is faster than the full o3 deep research model, with acceptable intelligence.\n",
+        "The Basic Research Agent performs Deep Research using the o4-mini-deep-research model. It has native WebSearch access to the public internet and streams its findings directly back into the notebook. In this case we are using the `o4-mini-deep-research` model, because it is faster than the full o3 deep research model, with acceptable intelligence.\n",
         "\n",
         "**Learning objective:**\n",
         "\n",