ci: Download and install glib2-doc manually
For some reason, dnf eats /usr/share/gtk-doc away in containers. We need the glib2 documentation for online docs to be found, and cross referencing to work.
Related: #324
For some reason, dnf eats /usr/share/gtk-doc away in containers. We need the glib2 documentation for online docs to be found, and cross referencing to work.
Related: #324