Bump ruff from 0.6.1 to 0.6.8

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.6.1 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@0.6.1...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

@@ -5,4 +5,4 @@ pytest >=7.1.3,<9.0.0
 pytest-asyncio==0.23.8
 pytest-cov >=2.12.0,<6.0.0
 pytest-django
-ruff ==0.6.1
+ruff ==0.6.8