Fix not staying buckled to a strap when both the buckled and the strap go into the same container

Content.Server/GameObjects/EntitySystems/BuckleSystem.cs

@@ -0,0 +1,34 @@
+using Content.Server.GameObjects.Components.Mobs;
+using Content.Server.GameObjects.EntitySystems.Click;
+using Robust.Server.GameObjects.EntitySystems;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    public class BuckleSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            EntityQuery = new TypeEntityQuery(typeof(BuckleComponent));
+
+            UpdatesAfter.Add(typeof(InteractionSystem));
+            UpdatesAfter.Add(typeof(InputSystem));
+        }
+
+        public override void Update(float frameTime)
+        {
+            foreach (var entity in RelevantEntities)
+            {
+                if (!entity.TryGetComponent(out BuckleComponent buckle))
+                {
+                    continue;
+                }
+
+                buckle.Update();
+            }
+        }
+    }
+}