Fix material storage going BRRT (#29167)

If the volume hits 0 we just remove it.

Content.Shared/Materials/SharedMaterialStorageSystem.cs

@@ -1,11 +1,13 @@
 using System.Linq;
 using Content.Shared.Interaction;
 using Content.Shared.Interaction.Components;
+using Content.Shared.Mobs;
 using Content.Shared.Stacks;
 using Content.Shared.Whitelist;
 using JetBrains.Annotations;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
+using Robust.Shared.Utility;
 
 namespace Content.Shared.Materials;
 
@@ -166,8 +168,14 @@ public abstract class SharedMaterialStorageSystem : EntitySystem
             return false;
         if (!CanChangeMaterialAmount(uid, materialId, volume, component))
             return false;
-        component.Storage.TryAdd(materialId, 0);
-        component.Storage[materialId] += volume;
+
+        var existing = component.Storage.GetOrNew(materialId);
+        existing += volume;
+
+        if (existing == 0)
+            component.Storage.Remove(materialId);
+        else
+            component.Storage[materialId] = existing;
 
         var ev = new MaterialAmountChangedEvent();
         RaiseLocalEvent(uid, ref ev);