[neon-notifications] Releasing: phonon - 4.12.0

[Neon CI]

https://build.neon.kde.org/job/watcher_release_extras_phonon/770/display/redirect

#<Debian::UScan::DEHS::Package:0x0000556e7038c078 @name="phonon", @debian_uversion="4.11.1", @debian_mangled_uversion="4.11.1", @upstream_version="4.12.0", @upstream_url="https://download.kde.internal.neon.kde.org/stable/phonon/4.12.0/phonon-4.12.0.tar.xz", @status="Newer version available">