Bump ruff from 0.6.8 to 0.8.1

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.6.8 to 0.8.1.
- [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...0.8.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -10,4 +10,4 @@ sphinx-rtd-theme==3.0.1
 pytest==8.3.3
 pytest-cov==5.0.0
 pyyaml==6.0.2
-ruff==0.6.8
+ruff==0.8.1