shallow copy animations array (#26416)

src/core/Object3D.js

@@ -945,7 +945,7 @@ class Object3D extends EventDispatcher {
 		this.frustumCulled = source.frustumCulled;
 		this.renderOrder = source.renderOrder;
 
-		this.animations = source.animations;
+		this.animations = source.animations.slice();
 
 		this.userData = JSON.parse( JSON.stringify( source.userData ) );