temporarily removed iridescence test models since they're still in development

tests/SharpGLTF.NUnit/TestFiles.cs

@@ -282,6 +282,8 @@ namespace SharpGLTF
 
         public IEnumerable<string> GetPaths(params string[] basePath)
         {
+            if (Name.Contains("Iridescence")) yield break; // still under development
+
             var rootPath = System.IO.Path.Combine(basePath);
 
             foreach(var variant in Variants)