[WIP] chore: update ElevenLabs tool. (#29722)

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---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

docs/docs/integrations/tools/eleven_labs_tts.ipynb

@@ -5,7 +5,7 @@
    "id": "a991a6f8-1897-4f49-a191-ae3bdaeda856",
    "metadata": {},
    "source": [
-    "# Eleven Labs Text2Speech\n",
+    "# ElevenLabs Text2Speech\n",
     "\n",
     "This notebook shows how to interact with the `ElevenLabs API` to achieve text-to-speech capabilities."
    ]
@@ -37,7 +37,7 @@
    "source": [
     "import os\n",
     "\n",
-    "os.environ[\"ELEVEN_API_KEY\"] = \"\""
+    "os.environ[\"ELEVENLABS_API_KEY\"] = \"\""
    ]
   },
   {