[neon-notifications] Dev Required: flatpak - 1.12.1

[Neon CI]

https://build.neon.kde.org/job/watcher_release_backports-focal_flatpak/18/display/redirect

#<Debian::UScan::DEHS::Package:0x0000559d32497e90 @name="flatpak", @debian_uversion="1.10.2", @debian_mangled_uversion="1.10.2", @upstream_version="1.12.1", @upstream_url="https://github.com/flatpak/flatpak/releases/download/1.12.1/flatpak-1.12.1.tar.xz", @status="Newer version available">