Automatically add trash tag to spent bullet casings (#40829)

* Automatically add trash tag to spent bullet casings

* Resolving comments

* 2

* Update Resources/Prototypes/Entities/Objects/Weapons/Guns/Ammunition/Cartridges/pistol.yml

---------

Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>

Content.Shared/Weapons/Ranged/Systems/SharedGunSystem.cs

@@ -65,6 +65,8 @@ public abstract partial class SharedGunSystem : EntitySystem
     [Dependency] private   readonly UseDelaySystem _useDelay = default!;
     [Dependency] private readonly EntityWhitelistSystem _whitelistSystem = default!;
 
+    private static readonly ProtoId<TagPrototype> TrashTag = "Trash";
+
     private const float InteractNextFire = 0.3f;
     private const double SafetyNextFire = 0.5;
     private const float EjectOffset = 0.4f;
@@ -452,6 +454,14 @@ public abstract partial class SharedGunSystem : EntitySystem
 
         cartridge.Spent = spent;
         Appearance.SetData(uid, AmmoVisuals.Spent, spent);
+
+        if (!cartridge.MarkSpentAsTrash)
+            return;
+
+        if (spent)
+            TagSystem.AddTag(uid, TrashTag);
+        else
+            TagSystem.RemoveTag(uid, TrashTag);
     }
 
     /// <summary>