This MR improves both jack device activation logic and device reservation logic by watching the dbus name:
If the dbus name does not have any owner for at least 3 seconds, wireplumber will try to acquire the name. If JACK is the dbus name owner, wireplumber will enable the JACK device and will disable the current audio device. If PipeWire is the dbus name owner, wireplumber will disable the JACK device and will enable the current audio device. If any other audio server (ie PulseAudio) is the dbus name owner, wireplumber will disable both JACK and audio devices.