Disable item dropping for a few NPCs in of0a0

Resolves twhl-community/halflife-op4-updated#72

src/HalfLife.UnifiedSdk.MapUpgrader.Upgrades/MapUpgradeBuilderExtensions.cs

@@ -31,6 +31,7 @@ public static MapUpgradeBuilder AddOpposingForceUpgrades(this MapUpgradeBuilder
             builder.AddAction(new ConvertScientistItemUpgrade());
             builder.AddAction(new RenameOtisAnimationsUpgrade());
             builder.AddAction(new MonsterTentacleSpawnFlagUpgrade());
+            builder.AddAction(new Of0a0DisableItemDroppingUpgrade());
             builder.AddAction(new Of1a4bChangeLoaderSkinUpgrade());
             builder.AddAction(new Of4a4BridgeUpgrade());
             builder.AddAction(new RenameBlackOpsAnimationsUpgrade());

src/HalfLife.UnifiedSdk.MapUpgrader.Upgrades/OpposingForce/Of0a0DisableItemDroppingUpgrade.cs

@@ -0,0 +1,29 @@
+using HalfLife.UnifiedSdk.Utilities.Entities;
+using HalfLife.UnifiedSdk.Utilities.Tools.UpgradeTool;
+using System.Collections.Immutable;
+
+namespace HalfLife.UnifiedSdk.MapUpgrader.Upgrades.OpposingForce
+{
+    /// <summary>
+    /// Disables item dropping for a couple NPCs in the Opposing Force intro map so players can't get weapons from them if they die.
+    /// </summary>
+    internal sealed class Of0a0DisableItemDroppingUpgrade : MapSpecificUpgradeAction
+    {
+        private static readonly ImmutableArray<string> NPCTargetNames = ImmutableArray.Create(
+            "ichabod",
+            "booth");
+
+        public Of0a0DisableItemDroppingUpgrade()
+            : base("of0a0")
+        {
+        }
+
+        protected override void ApplyCore(MapUpgradeContext context)
+        {
+            foreach (var entity in context.Map.Entities.Where(e => NPCTargetNames.Contains(e.GetTargetName())))
+            {
+                entity.SetInteger("allow_item_dropping", 0);
+            }
+        }
+    }
+}