mpd: Fix audio output being incorrectly detected as alsa

This fixes an issue where previously one would have to pause and play
audio tracks in order for them to play properly.

Upstream issue: https://github.com/MusicPlayerDaemon/MPD/issues/1649

home/ncmpcpp.nix

@@ -14,6 +14,11 @@ in
     inherit musicDirectory;
 
     extraConfig = ''
+      audio_output {
+        type "pipewire"
+        name "PipeWire Sound Server"
+      }
+
       auto_update "yes"
     '';
   };