chore(deps): bump flutter_gen_runner from 5.3.1 to 5.4.0 (#1272)

Bumps [flutter_gen_runner](https://github.com/FlutterGen/flutter_gen) from 5.3.1 to 5.4.0.
- [Release notes](https://github.com/FlutterGen/flutter_gen/releases)
- [Changelog](https://github.com/FlutterGen/flutter_gen/blob/main/CHANGELOG.md)
- [Commits](https://github.com/FlutterGen/flutter_gen/compare/v5.3.1...v5.4.0)

---
updated-dependencies:
- dependency-name: flutter_gen_runner
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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