Update tutorial cu116 -> cu118. (#5634)

notebooks/sparse/gcn.ipynb

@@ -11,7 +11,9 @@
     },
     "language_info": {
       "name": "python"
-    }
+    },
+    "accelerator": "GPU",
+    "gpuClass": "standard"
   },
   "cells": [
     {
@@ -39,7 +41,7 @@
         "# Uncomment below to install required packages. If the CUDA version is not 11.6,\n",
         "# check the https://www.dgl.ai/pages/start.html to find the supported CUDA\n",
         "# version and corresponding command to install DGL.\n",
-        "#!pip install dgl -f https://data.dgl.ai/wheels/cu116/repo.html > /dev/null\n",
+        "#!pip install dgl -f https://data.dgl.ai/wheels/cu118/repo.html > /dev/null\n",
         "\n",
         "try:\n",
         "    import dgl\n",
@@ -49,22 +51,10 @@
         "print(\"DGL installed!\" if installed else \"DGL not found!\")"
       ],
       "metadata": {
-        "colab": {
-          "base_uri": "https://localhost:8080/"
-        },
-        "id": "FTqB360eRvya",
-        "outputId": "df54b94e-fd1b-4b96-fca1-21948284254c"
+        "id": "FTqB360eRvya"
       },
       "execution_count": null,
-      "outputs": [
-        {
-          "output_type": "stream",
-          "name": "stdout",
-          "text": [
-            "DGL installed!\n"
-          ]
-        }
-      ]
+      "outputs": []
     },
     {
       "cell_type": "markdown",