[neon-notifications] khtml new version 5.73.0

[Neon CI]

https://build.neon.kde.org/job/watcher_release_kde_khtml/874/display/redirect

#<Debian::UScan::DEHS::Package:0x000055c2635be4a8 @name="khtml", @debian_uversion="5.72.0", @debian_mangled_uversion="5.72.0", @upstream_version="5.73.0", @upstream_url="https://download.kde.internal.neon.kde.org/stable/frameworks/5.73/portingAids/khtml-5.73.0.tar.xz", @status="Newer version available">