[FIX] Restore skybox enabling behavior (#1838)
[FIX] Restore skybox enabling behavior (#1838)

* added preUpdateHook

* fix particle system bug

* show the skybox layer on first update

Co-authored-by: Will Eastcott <37d41699bdee4fcb969ca499eb0f8b82c60d59cc@playcanvas.com>

MicroWorldwide/PlayCanvas,aidinabedi/playcanvas-engine,aidinabedi/playcanvas-engine,sereepap2029/playcanvas,playcanvas/engine,MicroWorldwide/PlayCanvas,sereepap2029/playcanvas,sereepap2029/playcanvas,playcanvas/engine