A bunch of cleanups and a missing ShortcutRegistar in WidgetsApp by @gspencergoog in https://github.com/flutter/flutter/pull/104560

Remove unused code from tests by @goderbauer in https://github.com/flutter/flutter/pull/104550

Removing Shorcuts.of and Shortctus.maybeOf by @gspencergoog in https://github.com/flutter/flutter/pull/104215

Cleanup random dead test code by @goderbauer in https://github.com/flutter/flutter/pull/104568

Use curly_braces_in_flow_control_structures for foundation, gestures, painting, physics by @guidezpl in https://github.com/flutter/flutter/pull/104610