docs: pinecone client version note (#17491)

docs/docs/integrations/vectorstores/pinecone.ipynb

@@ -37,6 +37,14 @@
     "%pip install --upgrade --quiet  langchain-pinecone langchain-openai langchain"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "1917d123",
+   "metadata": {},
+   "source": [
+    "Migration note: if you are migrating from the `langchain_community.vectorstores` implementation of Pinecone, you may need to remove your `pinecone-client` v2 dependency before installing `langchain-pinecone`, which relies on `pinecone-client` v3."
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "42f2ea67",