chore(deps): bump ruff from 0.15.8 to 0.15.12

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.15.8 to 0.15.12.
- [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...0.15.12)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.15.12
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements.txt

@@ -2,4 +2,4 @@ slack-bolt==1.27.0
 requests==2.33.1
 Flask==3.1.3
 pytest==9.0.2
-ruff==0.15.8
+ruff==0.15.12