Bump ruff from 0.6.3 to 0.6.8

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.6.3 to 0.6.8.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.6.3...0.6.8)

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

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

Author: dependabot[bot]

requirements-tests.txt

@@ -9,4 +9,4 @@ mypy == 1.11.2
 pytest >= 7.1.3,< 9.0.0
 pytest-asyncio
 pytest-cov >= 2.12.0,< 6.0.0
-ruff ==0.6.3
+ruff ==0.6.8