fix: Remove material observable notification in babylon file loader

src/Loading/Plugins/babylon.babylonFileLoader.ts

@@ -73,7 +73,6 @@
                     var parsedMaterial = parsedData.materials[index];
                     var mat = Material.Parse(parsedMaterial, scene, rootUrl);
                     container.materials.push(mat);
-                    container.scene.onNewMaterialAddedObservable.notifyObservers(mat);
                     log += (index === 0 ? "\n\tMaterials:" : "");
                     log += "\n\t\t" + mat.toString(fullDetails);
                 }