feat: download dataset from Google Drive when running locally

- Add  dep to requirements.txt
- Non-Colab path: download dataset_jagung.zip from Drive using file ID
  if not present locally, then extract as usual
- Keeps Colab path unchanged (drive.mount)

Co-Authored-By: Claude <noreply@anthropic.com>

Machine_Learning/requirements.txt

@@ -1,5 +1,6 @@
 tensorflow==2.19.0              # CPU + Colab; for local GPU, install tensorflow[and-cuda]
 tensorflowjs==4.22.0
+gdown                           # download dataset from Google Drive
 numpy
 matplotlib
 seaborn