[Experimental] [3D foliage swaying] Remove the namespace (#2129)

- Don't show in changelog

Author: D8H

extensions/community/FoliageSwaying3D.json

@@ -2,7 +2,7 @@
   "author": "",
   "category": "3D",
   "dimension": "3D",
-  "extensionNamespace": "FoliageSwaying",
+  "extensionNamespace": "",
   "fullName": "3D foliage swaying",
   "gdevelopVersion": "",
   "helpPath": "",