Install "GNOME OS" under the Boxes custom osinfo-db
Our Flatpak now has a OsinfoDb extension that will install data on what libosinfo considers the "system" path. This way, the GNOME OS nightly osinfo-db entries would get overwritten by the extension.
By installing them under our custom osinfo database they can co-exist with the libosinfo "system" osinfo-db.
See https://github.com/flathub/org.gnome.Boxes.Extension.OsinfoDb