added support for IDisposable for DataLoaders

Author: robertdorn83

Runtime/Scripts/GLTFSceneImporter.cs

@@ -408,6 +408,8 @@ private void VerifyDataLoader()
 
 		public void Dispose()
 		{
+			if (_options.DataLoader is IDisposable disposable)
+				disposable.Dispose();
 			Cleanup();
 			DisposeNativeBuffers();
 		}