Remove audio-playback from snap plugs

electron-builder adds it by default already.

The duplicate entry causes error when uploading:
Error found while validating snap.json::$.apps.turbowarp-desktop.plugs: ['desktop', 'desktop-legacy', 'home', 'x11', 'wayland', 'unity7', 'browser-support', 'network', 'gsettings', 'audio-playback', 'pulseaudio', 'opengl', 'camera', 'audio-playback', 'audio-record', 'joystick', 'removable-media'] has non-unique elements lint-snap-v2_snap_schema

Author: GarboMuffin

package.json

@@ -183,7 +183,6 @@
       "plugs": [
         "default",
         "camera",
-        "audio-playback",
         "audio-record",
         "joystick",
         "removable-media"