运行报错 Cannot run with sound null safety, because the following dependencies

升级后，运行报错：

Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

 - package:toast

For solutions, see https://dart.dev/go/unsound-null-safety

Command PhaseScriptExecution failed with a nonzero exit code

解决方案: --no-sound-null-safety

## run
flutter run --no-sound-null-safety
## build
flutter build apk --no-sound-null-safety

引用资料：解决方案