Add missing ninja dependency

Somehow ninja was missing in colab. Added that

Also changed `pip install .` to `python3 setup.py install` - some error with pip in resolving the path of extension (happening in python 3.12, didnt happen in 3.11)

notebooks/demo.ipynb

@@ -133,7 +133,7 @@
         "# TODO check for gcc-11 or above\n",
         "\n",
         "# Install pip packages\n",
-        "pip install --upgrade pip setuptools wheel\n",
+        "pip install --upgrade pip setuptools wheel ninja\n",
         "pip install -r requirements.txt\n",
         "\n",
         "cd models/GroundingDINO/ops\n",
@@ -143,12 +143,12 @@
         "    then\n",
         "        echo \"failed to install wheel, trying to build from source\";\n",
         "        python3 setup.py build\n",
-        "        pip install .\n",
+        "        python3 setup.py install .\n",
         "    fi\n",
         "else\n",
         "    # We try to build the module as we dont know what environment we are running on\n",
         "    python3 setup.py build\n",
-        "    pip install .\n",
+        "    python3 setup.py install .\n",
         "fi\n",
         "python3 test.py"
       ]