Bump ruff from 0.5.5 to 0.5.6

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.5.5 to 0.5.6.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.5.5...0.5.6)

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

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

pyproject.toml

@@ -44,7 +44,7 @@ prometheus-xmpp-alerts = "prometheus_xmpp.__main__:main"
 
 [project.optional-dependencies]
 testing = ["pytz"]
-dev = ["ruff==0.5.5"]
+dev = ["ruff==0.5.6"]
 
 [tool.setuptools]
 packages = ["prometheus_xmpp"]