Bump vulture from 2.1 to 2.3

Bumps [vulture](https://github.com/jendrikseipp/vulture) from 2.1 to 2.3.
- [Release notes](https://github.com/jendrikseipp/vulture/releases)
- [Changelog](https://github.com/jendrikseipp/vulture/blob/master/CHANGELOG.md)
- [Commits](jendrikseipp/vulture@v2.1...v2.3)

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

requirements.txt

@@ -17,4 +17,4 @@ pytest-cov==2.10.1
 pytest-socket==0.3.5
 queueman==0.5
 requests==2.25.1
-vulture==2.1
+vulture==2.3