fix: resolve CI failures for notebook update

- Fix broken link: update multitenancy docs URL to /guides/index-data/
- Remove explicit pinecone==8.0.0 which conflicts with langchain-pinecone
  (langchain-pinecone 0.2.13 requires pinecone<8.0.0)

The langchain-pinecone package will bring in the compatible pinecone
version (7.x) as a transitive dependency.

Author: jhamon

docs/rag-getting-started.ipynb

@@ -56,7 +56,6 @@
    "outputs": [],
    "source": [
     "!pip install -qU \\\n",
-    "    pinecone==8.0.0 \\\n",
     "    langchain-pinecone==0.2.13 \\\n",
     "    langchain-openai==0.3.0 \\\n",
     "    langchain-text-splitters==0.3.5 \\\n",
@@ -307,7 +306,7 @@
     "id": "IekoI7HNtsVj"
    },
    "source": [
-    "Embed and upsert each chunk as a distinct record in a namespace called `wondervector5000`. Namespaces let you partition records within an index and are essential for [implementing multitenancy](https://docs.pinecone.io/guides/indexes/implement-multitenancy) when you need to isolate the data of each customer/user."
+    "Embed and upsert each chunk as a distinct record in a namespace called `wondervector5000`. Namespaces let you partition records within an index and are essential for [implementing multitenancy](https://docs.pinecone.io/guides/index-data/implement-multitenancy) when you need to isolate the data of each customer/user."
    ]
   },
   {