Put a warning sign for cell that should not be run locally

Addresses #78

data_processing.ipynb

@@ -117,30 +117,19 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# Install packages on system\n",
-    "# ℹ️ No need to run this cell if you run this notebook locally and already have these dependencies installed.\n",
+    "# ⚠️ No need to run this cell if you run this notebook locally and already have these dependencies installed.\n",
     "\n",
+    "# Install packages on system\n",
     "!sudo apt-get update\n",
     "!sudo apt-get install git-annex\n",
     "\n",
     "# Install Python libaries\n",
     "!wget -O requirements.txt https://raw.githubusercontent.com/shimming-toolbox/rf-shimming-7t/main/requirements.txt\n",
-    "!pip install -r requirements.txt"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "4238e452",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# Install SCT ⏳\n",
-    "# ℹ️ No need to run this cell if you run this notebook locally and already have SCT installed.\n",
+    "!pip install -r requirements.txt\n",
     "\n",
+    "# Install SCT ⏳\n",
     "!git clone --depth 1 https://github.com/spinalcordtoolbox/spinalcordtoolbox.git\n",
     "!yes | spinalcordtoolbox/install_sct\n",
-    "# Add SCT's binaries to environment PATH\n",
     "os.environ['PATH'] += f\":/content/spinalcordtoolbox/bin\""
    ]
   },