Bump ruff from 0.15.8 to 0.15.9 in /tools/third_party

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](astral-sh/ruff@0.15.8...0.15.9)

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

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

Author: dependabot[bot]

tools/third_party/pyproject.toml

@@ -15,7 +15,7 @@ dependencies = [
     "mypy==1.20.0",
     "pip-audit==2.10.0",
     "pyproject-fmt==2.21.0",
-    "ruff==0.15.8",
+    "ruff==0.15.9",
     "troml==0.4.1",
     "unittest-xml-reporting==4.0.0", # Needed to generate JUnit XML output for Sonarcloud.io
     "vulture==2.16",