docs: remove docs on hold note in `CONTRIBUTING.md` (#8598)
docs: remove docs on hold note in `CONTRIBUTING.md` (#8598)


firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire