serv4 + submodule update (#12740)

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Server/Salvage/SalvageMagnetComponent.cs

@@ -1,7 +1,7 @@
 using Content.Shared.Radio;
-using Content.Shared.Salvage;
 using Robust.Shared.GameStates;
 using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+using Content.Shared.Salvage;
 
 namespace Content.Server.Salvage
 {
@@ -66,6 +66,7 @@ namespace Content.Server.Salvage
         public int PreviousCharge = 5;
 
     }
+    [CopyByRef]
     public record struct MagnetState(MagnetStateType StateType, TimeSpan Until)
     {
         public static readonly MagnetState Inactive = new (MagnetStateType.Inactive, TimeSpan.Zero);