BuildContext across async gaps false positive for null-aware access + null operator

[vendelin8]

Describe the issue
Lint error use_build_context_synchronously when it was already checked

To Reproduce

final GlobalKey<NavigatorState> navKey = GlobalKey<NavigatorState>();

Future<void> newPhoto() async {
  await Future.delayed(const Duration(seconds: 1));
  final context = navKey.currentContext;
  if (!(context?.mounted ?? false)) {
    return;
  }
  Navigator.of(context!).pop(); // <- LINT ERROR HERE 
}

In an updated repo for this bug: https://github.com/vendelin8/dart-lintbug

Expected behavior
No lint infos, because mounted was already checked previously.

Additional context

dart --version
Dart SDK version: 3.5.4 (stable) (Wed Oct 16 16:18:51 2024 +0000) on "linux_x64"

[bwilkerson]

This lint doesn't currently handle flow paths of that level of complexity. It isn't clear that we will expand it to handle this kind of code.

As a work-around, I'd suggest using an 'ignore' comment.