Unrevert audio (#21330)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>

Content.Server/Medical/DefibrillatorSystem.cs

@@ -19,6 +19,7 @@ using Content.Shared.Mobs.Systems;
 using Content.Shared.PowerCell;
 using Content.Shared.Timing;
 using Content.Shared.Toggleable;
+using Robust.Shared.Audio.Systems;
 using Robust.Shared.Player;
 using Robust.Shared.Timing;