Bump pbr from 6.0.0 to 6.1.0

Bumps [pbr](https://docs.openstack.org/pbr/latest/) from 6.0.0 to 6.1.0.

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

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

requirements.txt

@@ -104,7 +104,7 @@ django-smtp-ssl==1.0
 ctlsettings==0.3.2
 confusable_homoglyphs==3.3.0
 
-pbr==6.0.0
+pbr==6.1.0
 PyYAML>=3.10.0 # MIT
 stevedore>=1.20.0 # Apache-2.0
 bandit==1.7.1