chore(deps-dev): bump ruff from 0.15.8 to 0.15.9

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.15.8 to 0.15.9.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](https://github.com/astral-sh/ruff/compare/0.15.8...0.15.9)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.15.9
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

requirements-dev.txt

@@ -6,7 +6,7 @@
 -r requirements-freqai-rl.txt
 -r docs/requirements-docs.txt
 
-ruff==0.15.8
+ruff==0.15.9
 mypy==1.20.0
 pre-commit==4.5.1
 pytest==9.0.2