Add missing dep in lcel cookbook (#10636)

Add missing dependency

docs/extras/expression_language/cookbook/retrieval.ipynb

@@ -21,17 +21,17 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "id": "7f25d9e9-d192-42e9-af50-5660a4bfb0d9",
    "metadata": {},
    "outputs": [],
    "source": [
-    "!pip install langchain openai faiss-cpu"
+    "!pip install langchain openai faiss-cpu tiktoken"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 10,
    "id": "33be32af",
    "metadata": {},
    "outputs": [],
@@ -48,7 +48,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 6,
    "id": "bfc47ec1",
    "metadata": {},
    "outputs": [],
@@ -83,7 +83,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 18,
    "id": "f3040b0c",
    "metadata": {},
    "outputs": [
@@ -439,9 +439,9 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "poetry-venv",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
-   "name": "poetry-venv"
+   "name": "python3"
   },
   "language_info": {
    "codemirror_mode": {
@@ -453,7 +453,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.1"
+   "version": "3.11.4"
   }
  },
  "nbformat": 4,