pipewire: Add support for Focusrite Scarlett Solo Gen 3

The headphone output of my Behringer UMC202HD had sporadic cutouts.
While short, they were quite annoying.

I hope this interface (which costs 50% more) will work better.

modules/pipewire.nix

@@ -19,8 +19,14 @@ lib.mkIf config.sbruder.gui.enable {
     unstable.helvum # patch panel
     pavucontrol
     pulseaudio # pacmd and pactl
+    alsa-scarlett-gui # focusrite scarlett control
   ];
 
   hardware.bluetooth.enable = lib.mkDefault bluetoothSupport;
   services.blueman.enable = lib.mkDefault bluetoothSupport;
+
+  boot.extraModprobeConfig = ''
+    # Focusrite Scarlett Solo Gen 3 Mixer Driver
+    options snd_usb_audio vid=0x1235 pid=0x8211 device_setup=1
+  '';
 }