Re-enable Sass CSS compression
Re-enable Sass CSS compression

Accidentally removed during Rails 7 upgrade and was causing errors in production.

Originally added here: https://github.com/alphagov/service-manual-publisher/commit/23690ae327362dd5feace4167c089801cb13ef07

alphagov/service-manual-publisher,alphagov/service-manual-publisher,alphagov/service-manual-publisher