build(deps-dev): bump ruff from 0.12.7 to 0.12.8 in /clients/python (kubeflow#1449)

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.12.7 to 0.12.8.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.12.7...0.12.8)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.12.8
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]