[neon-notifications] Dev Required: qxmpp - 1.6.0

[Neon CI]

https://build.neon.kde.org/job/watcher_release_backports-jammy_qxmpp-jammy/375/display/redirect

#<Debian::UScan::DEHS::Package:0x00005641f0096068 @name="qxmpp", @debian_uversion="1.5.5", @debian_mangled_uversion="1.5.5", @upstream_version="1.6.0", @upstream_url="https://github.com/qxmpp-project/qxmpp/archive/refs/tags/v1.6.0.tar.gz", @status="Newer version available">