[neon-notifications] Releasing: ktnef - 21.04.3

[Neon CI]

https://build.neon.kde.org/job/watcher_release_kde_ktnef/1197/display/redirect

#<Debian::UScan::DEHS::Package:0x0000564c787ea228 @name="ktnef", @debian_uversion="21.04.2", @debian_mangled_uversion="21.04.2", @upstream_version="21.04.3", @upstream_url="http://download.kde.internal.neon.kde.org/stable/release-service/21.04.3/src/ktnef-21.04.3.tar.xz", @status="Newer version available">