The Flatpak version of appstream-glib alters the behaviour of the appstream-util validate quite a bit, with the ultimate result being somewhere between the original validate and validate-relax subcommands. Since the validation here is mainly aimed at fulfilling Flathub's requirements, and Flathub itself uses org.freedesktop.appstream-glib to validate AppStream files, it's only natural to use the same here in CI.
The Flatpak version of appstream-glib alters the behaviour of the
appstream-util validatequite a bit, with the ultimate result being somewhere between the originalvalidateandvalidate-relaxsubcommands. Since the validation here is mainly aimed at fulfilling Flathub's requirements, and Flathub itself usesorg.freedesktop.appstream-glibto validate AppStream files, it's only natural to use the same here in CI.