community: Fix Baichuan Chat. (#15207)

- **Description:** Baichuan Chat (with both Baichuan-Turbo and
Baichuan-Turbo-192K models) has updated their APIs. There are breaking
changes. For example, BAICHUAN_SECRET_KEY is removed in the latest API
but is still required in Langchain. Baichuan's Langchain integration
needs to be updated to the latest version.
  - **Issue:** #15206
  - **Dependencies:** None,
  - **Twitter handle:** None

@hwchase17.

Co-authored-by: BaiChuanHelper <wintergyc@WinterGYCs-MacBook-Pro.local>

docs/docs/integrations/chat/baichuan.ipynb

@@ -13,7 +13,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# ChatBaichuan\n",
+    "# Chat with Baichuan-192K\n",
     "\n",
     "Baichuan chat models API by Baichuan Intelligent Technology. For more information, see [https://platform.baichuan-ai.com/docs/api](https://platform.baichuan-ai.com/docs/api)"
    ]
@@ -44,19 +44,16 @@
    },
    "outputs": [],
    "source": [
-    "chat = ChatBaichuan(\n",
-    "    baichuan_api_key=\"YOUR_API_KEY\", baichuan_secret_key=\"YOUR_SECRET_KEY\"\n",
-    ")"
+    "chat = ChatBaichuan(baichuan_api_key=\"YOUR_API_KEY\")"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "or you can set `api_key` and `secret_key` in your environment variables\n",
+    "or you can set `api_key` in your environment variables\n",
     "```bash\n",
     "export BAICHUAN_API_KEY=YOUR_API_KEY\n",
-    "export BAICHUAN_SECRET_KEY=YOUR_SECRET_KEY\n",
     "```"
    ]
   },
@@ -91,7 +88,7 @@
     "collapsed": false
    },
    "source": [
-    "## For ChatBaichuan with Streaming"
+    "## Chat with Baichuan-192K with Streaming"
    ]
   },
   {
@@ -108,7 +105,6 @@
    "source": [
     "chat = ChatBaichuan(\n",
     "    baichuan_api_key=\"YOUR_API_KEY\",\n",
-    "    baichuan_secret_key=\"YOUR_SECRET_KEY\",\n",
     "    streaming=True,\n",
     ")"
    ]