It’s trivial, like setting sys-net, or sys-usb today You take fedora-36-minimal, clone it, install needed packages and set it aside. Then you run
In dom0:
sudo qubes-dom0-update qubes-audio-dom0
sudo qubesctl state.sls qvm.sys-audio
and assign sys-audio as audiovm to some qube.
qvm-prefs <targetVM> audiovm sys-audio
You can also use this to set sys-audio as default audiovm for all other qubes:
qubes-prefs default_audiovm sys-audio
Attach sound controller to sys-audio, and reboot.
Test.
If you can’t boot, do not panic. It’s solvable most probably.
When confirming it runs based on fedora-36, just switch sys-audio template to fedora-36-minimal from above.
Test.
If it doesn’t work either way, just return the controller back to dom0 and reboot.