Fix CI Fedora builds (gtk subproject + new libadwaita)
With DNF5 we need dnf5-plugins to provide the builddep feature used for building the gtk subproject dependencies in our CI builds.
We also need the sassc dependency for libadwaita.
With DNF5 we need dnf5-plugins to provide the builddep feature used for building the gtk subproject dependencies in our CI builds.
We also need the sassc dependency for libadwaita.