[neon-notifications] Dev Required: libgusb - 0.3.9

[Neon CI]

https://build.neon.kde.org/job/watcher_release_backports-focal_libgusb/92/display/redirect

#<Debian::UScan::DEHS::Package:0x0000559564bc88c0 @name="libgusb", @debian_uversion="0.3.8", @debian_mangled_uversion="0.3.8", @upstream_version="0.3.9", @upstream_url="https://people.freedesktop.org/~hughsient/releases/libgusb-0.3.9.tar.xz", @status="Newer version available">