flutter 3.0.1 linter

./../../flutter/.pub-cache/hosted/pub.dartlang.org/time_picker_widget-1.0.0+10/lib/time_picker_widget.dart:878:39: Warning: Operand of null-aware operation '!' has type 'PaintingBinding' which excludes null.

• 'PaintingBinding' is from 'package:flutter/src/painting/binding.dart' ('../../../flutter/packages/flutter/lib/src/painting/binding.dart'). }) : super(repaint: PaintingBinding.instance!.systemFonts);