[neon-notifications] Releasing: kstars - 3.7.3

[Neon CI]

https://build.neon.kde.org/job/watcher_release_extras_kstars/54/display/redirect

#<Debian::UScan::DEHS::Package:0x00007f4e1c5cc760 @name="kstars", @debian_uversion="3.7.2", @debian_mangled_uversion="3.7.2", @upstream_version="3.7.3", @upstream_url="https://download.kde.internal.neon.kde.org/stable/kstars/3.7.3/kstars-3.7.3.tar.xz", @status="Newer version available">