[flax:examples:sst2] Fix notebook error.

PiperOrigin-RevId: 839349552

Author: danielsuo

examples/sst2/sst2.ipynb

@@ -86,6 +86,7 @@
     "  # Download Flax repo from Github.\n",
     "  if not os.path.isdir('flaxrepo'):\n",
     "    !git clone --depth=1 https://github.com/google/flax flaxrepo\n",
+    "    pass\n",
     "  # Copy example files & change directory.\n",
     "  mount_gdrive = 'no' #@param ['yes', 'no']\n",
     "  if mount_gdrive == 'yes':\n",
@@ -274,4 +275,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 0
-}
+}