build(deps-dev): bump the app-dev group in /app with 2 updates

Bumps the app-dev group in /app with 2 updates: [boto3-stubs](https://github.com/youtype/mypy_boto3_builder) and [ruff](https://github.com/astral-sh/ruff).


Updates `boto3-stubs` from 1.35.30 to 1.35.39
- [Release notes](https://github.com/youtype/mypy_boto3_builder/releases)
- [Commits](https://github.com/youtype/mypy_boto3_builder/commits)

Updates `ruff` from 0.6.8 to 0.6.9
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.6.8...0.6.9)

---
updated-dependencies:
- dependency-name: boto3-stubs
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: app-dev
- dependency-name: ruff
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: app-dev
...

Signed-off-by: dependabot[bot] <[email protected]>