Bump vobject from 0.9.8 to 0.9.9

Bumps [vobject](https://github.com/py-vobject/vobject) from 0.9.8 to 0.9.9.
- [Release notes](https://github.com/py-vobject/vobject/releases)
- [Commits](py-vobject/vobject@v0.9.8...v0.9.9)

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

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

requirements.txt

@@ -40,7 +40,7 @@ requests==2.32.3
 sqlalchemy==2.0.36  # Required by Celery broker transport
 urllib3==1.26.18
 uWSGI==2.0.28
-vobject==0.9.8
+vobject==0.9.9
 whitenoise==5.2.0
 titlecase==2.4.1
 social-auth-app-django==5.4.2