For anyone updating to Riverpod ^3.0.0,
Riverpod has moved StateProvider, StateNotifierProvider, and ChangeNotifierProvider to legacy state and soon be deprecating them in favor of newer Notifier API
https://riverpod.dev/docs/3.0_migration#stateprovider-statenotifierprovider-and-changenotifierprovider-are-moved-to-a-new-import
Now, it is encouraged to use StateNotifier and StateNotifierProvider
https://riverpod.dev/docs/migration/from_state_notifier#new-syntax-comparison