KPipeWire dependency

[Aleix Pol]

Hi,
Just a quick note that I've merged the plasma-desktop MR that switches
to using KPipeWire instead of the components within plasma-workspace.
https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/949
https://invent.kde.org/plasma/plasma-mobile/-/merge_requests/242#

This means it becomes a dependency for the master branch and thus the
unstable builds.

Cheers!
Aleix