Describe the bug
I'm using --no-sound-null-safety due to legacy dependency. I can't run test by clicking hovering Run / Debug button above code since 3.24.0 upgrade.

To Reproduce

Be aware branch.

git clone https://github.com/jeiea/flutter_example.git -b flutter_additional_args
cd flutter_example
flutter pub get
code .

Open test/widget_test.dart and click Run or Debug text button around line 15.

Expected behavior
Test execution.

Screenshots

Versions:

➜  code --version
1.57.1
507ce72a4466fbb27b715c3722558bb15afa9f48
x64
➜  code --list-extensions --show-versions | rg Dart
Dart-Code.dart-code@3.24.0
Dart-Code.flutter@3.24.0
➜  flutter --version
Flutter 2.2.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision f4abaa0735 (3 days ago) • 2021-07-01 12:46:11 -0700
Engine • revision 241c87ad80
Tools • Dart 2.13.4