Outdated doc on Managing node groups

[jsjtxietian]

Your Godot version:
Godot v4.3.dev (29b3d9e9e)

Issue description:
Due to godotengine/godot#60965 we can manage node groups from the project settings and thus this page is outdated.

URL to the documentation page:

https://docs.godotengine.org/en/latest/tutorials/scripting/groups.html

[skyace65]

Fixed by #9461.