Conflicts:
- `.github/dependabot.yml`:
  Upstream made changes while we have dropped this file.
  Keep the file deleted.
- `.prettierignore`:
  Upstream made changes at the end of the file, where we
  had our extra lines.
  Just moved our extra lines back at the end.
- `app/serializers/initial_state_serializer.rb`:
  Upstream code style changes.
  Applied them.
- `app/services/backup_service.rb`:
  Upstream code style changes.
  Applied them.