Addons: export GroundedSkybox. (#27459)

examples/jsm/Addons.js

@@ -160,7 +160,7 @@ export * from './modifiers/EdgeSplitModifier.js';
 export * from './modifiers/SimplifyModifier.js';
 export * from './modifiers/TessellateModifier.js';
 
-export * from './objects/GroundProjectedSkybox.js';
+export * from './objects/GroundedSkybox.js';
 export * from './objects/Lensflare.js';
 export * from './objects/MarchingCubes.js';
 export * from './objects/Reflector.js';