Do not use, this is PoC project which works for me, but will require some fiddling for anyone else.
I have sonos speaker, which work through pulseaudio raop module.
The problem is, pulseaudio raop discovery works with avahi zeroconf server, and not thru systemd-resolved mdns support, which I want to use, because I hate avahi messing with my complicated networking setup.
Solution? Use resolved dbus api to discover raop devices, and attach them to pipewire server.
Only caveat is that server should be restarted if any of sonos devices change their address, because disconnected devices are not being removed, but that is not a problem for me, because my wireplumber setup automaticly connects to the most recently discovered sonos speaker for each room.
It also doesn’t work with ipv6, because raop-sink module doesn’t have ability to provide interface for link-local addresses.