[flutter] 플러터 2.5 버전 업데이트

업데이트 항목

1. Performance : iOS shader warmup, async tasks , GC & message passing
2. Dart 2.14: formatting, language features, pub & listing out-of-the-box
3. Framework: Android full screen, Material You & text editing shortcuts
4. Plugins : camera, image picker & plus plugins
5. Flutter DevTools : performance , Widget inspector & polish
6. IntelliJ/Android Studio: intergration tests, test coverage, and icon previews
7. Tools: exceptions, new app template & Pigeon 1.0