New package python-django-libsass and python-libsass are required in RDO as Horizon project wants to replace pyscss.
More details in [1][2]

django-libsass upstream repo: https://github.com/torchbox/django-libsass/
libsass upstream repo: https://github.com/sass/libsass-python
 
[1] https://review.opendev.org/c/openstack/requirements/+/934220
[2] https://review.opendev.org/c/openstack/horizon/+/934143