chore(deps): bump vulture from 2.6 to 2.9 in /dev_requirements

Bumps [vulture](https://github.com/jendrikseipp/vulture) from 2.6 to 2.9.
- [Release notes](https://github.com/jendrikseipp/vulture/releases)
- [Changelog](https://github.com/jendrikseipp/vulture/blob/main/CHANGELOG.md)
- [Commits](jendrikseipp/vulture@v2.6...v2.9)

---
updated-dependencies:
- dependency-name: vulture
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

dev_requirements/linter-requirements.txt

@@ -10,4 +10,4 @@ pyflakes==2.4.0
 pylint==2.13.5
 readme_renderer==37.3
 seed-isort-config==2.2.0
-vulture==2.6
+vulture==2.9