delete method
Deletes the data associated with key.
If key does not exist, this method should do nothing.
This method will usually be called by NotifierPersistX.persist when either
StorageOptions.destroyKey changes or StorageOptions.cacheTime expires.
Implementation
@override
Future<void> delete(String key) async {
final riverpodKey = Helpers.computeRiverpodKey(key);
final _ = await prefs.remove(riverpodKey);
}