[neon-notifications] Dev Required: pipewire - 1.6.8

[Neon CI]

https://build.neon.kde.org/job/watcher_release_backports-noble_pipewire-noble/536/display/redirect

#<Debian::UScan::DEHS::Package:0x000075a0e30d3168 @name="pipewire", @debian_uversion="1.2.6", @debian_mangled_uversion="1.2.6", @upstream_version="1.6.8", @upstream_url="https://gitlab.freedesktop.org/pipewire/pipewire/-/archive/1.6.8/pipewire-1.6.8.tar.bz2", @status="Newer version available">