Remove GhoulSkin render node worker

Deleted PawnRenderNodeWorker_GhoulSkin.cs, which provided a custom render node worker for ghoul skin coloring. This may be part of a refactor or removal of unused code.

Source/FCP_Ghoul/PawnRenderNodeWorker_GhoulSkin.cs

@@ -1,14 +0,0 @@
-using UnityEngine;
-using Verse;
-
-namespace FCP_Ghoul
-{
-    public class PawnRenderNodeWorker_GhoulSkin : PawnRenderNodeWorker_Fur
-    {
-        public override Color ColorFor(PawnRenderNode node)
-        {
-            // Force the body to use the exact same color as the pawn's skin
-            return node.Props.color.GetValueOrDefault(node.tree.pawn.story.SkinColor);
-        }
-    }
-}