Add pulseaudio

This is needed to output the sound of the videos

Author: rolandgeider

flatpak/flatpak_meta.json

@@ -23,6 +23,7 @@
         "--share=network",
         "--socket=fallback-x11",
         "--socket=wayland",
+        "--socket=pulseaudio",
         "--device=dri"
     ]
 }