Welcome to Manjaro forum @opensourcealltheway
Previous comments about PulseAudio and PipeWire running at the same time were based on misrepresentation of data from inxi -Aa (package was updated to show better information)
If you want to replace pulseaudio with pipewire-pulse and wireplumber all you need is
pamac install manjaro-pipewire
Error: Failed to prepare transaction: target not found: wireplumber
check if download mirrors are up to date - https://repo.manjaro.org/