silverblue: build from Everything repo
    
    There are several recommends packages that aren't getting installed in
    Silverblue because the workstation comps group doesn't include them.
    One of these is slirp4netns which is needed for rootless containers
    using podman.
    
    Since we are thinking about removing the separate Workstation repo
    anyway[1], then maybe we can just move SB over to the Everything repo.
    
    [1] https://pagure.io/releng/issue/7403
    
    Signed-off-by: Dusty Mabe <dusty@dustymabe.com>