build(deps-dev): bump ruff from 0.5.7 to 0.6.9

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.5.7 to 0.6.9.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.5.7...0.6.9)

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

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

pyproject.toml

@@ -33,7 +33,7 @@ beangulp = "^0.1.1"
 taskipy = "^1.13.0"
 black = "^24.4.2"
 pytest = "^8.2.2"
-ruff = "^0.5.7"
+ruff = ">=0.5.7,<0.7.0"
 
 [tool.poetry.scripts]
 beancount-n26-ec = "beancount_n26.cli:ec"