[iOS] 'Flutter/Flutter.h' file not found when flutter run on iOS 오류

참고 : https://stackoverflow.com/questions/64973346/error-flutter-flutter-h-file-not-found-when-flutter-run-on-ios

해결책 : 아래 순서대로 하시면 됩니다.

1. Backup ios/Runner folder.
2. Delete the ios folder.
3. Run flutter create (your project name). in the previous folder where you have your project(cd users/user/"projects_folder") (this will recreate your ios folder).
4. Paste your Runner backup in the ios folder (into the project).
5. Open Runner.xcworkspace (into ios folder) and there, check the Version, the Bundle ID, all the info.
6. (If do you Have Firebase, you have to copy and paste again the Google Service-Info.Plist into the Runner folder (Always through Xcode) (If do you do this manually, it doesn't work ⇒ 이거 Runner/Runner에 넣어야 한다).

추가 : 만약 Flutter 3.0으로 migration 이후 위 오류가 발생한다면, 오류가 발생하는 라이브러리를 찾아서 해당 라이브러리를 Flutter 3.0이 대응되는 최신 버전으로 업데이트해서 해결하셔야 합니다.