[neon-notifications] Releasing: kstars - 3.5.6

[Neon CI]

https://build.neon.kde.org/job/watcher_release_extras_kstars/55/display/redirect

#<Debian::UScan::DEHS::Package:0x000055e0a4765860 @name="kstars", @debian_uversion="3.5.5", @debian_mangled_uversion="3.5.5", @upstream_version="3.5.6", @upstream_url="http://download.kde.internal.neon.kde.org/stable/kstars/kstars-3.5.6.tar.xz", @status="Newer version available">