Mark cutout_animation as outdated

This tutorial no longer works in Godot 4.x after the Skeletons section.

https://github.com/godotengine/godot-docs/issues/7279
https://github.com/godotengine/godot-docs/issues/6388

tutorials/animation/cutout_animation.rst

@@ -1,3 +1,5 @@
+:article_outdated: True
+
 .. _doc_cutout_animation:
 
 Cutout animation