Update ruff requirement from <0.8 to <0.9

Updates the requirements on [ruff](https://github.com/astral-sh/ruff) to permit the latest version.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@v0.0.18...0.8.0)

---
updated-dependencies:
- dependency-name: ruff
  dependency-type: direct:development
...

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

setup.py

@@ -68,7 +68,7 @@ def read(path):
             "createcoverage>=1,<2",
             "mypy<1.14",
             "poethepoet<0.32",
-            "ruff<0.8",
+            "ruff<0.9",
             "stopit>=1.1.2,<2",
             "tox>=3,<5",
             "pytz",