Fix limitation on sky size

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Sky/SkyManager.cs

         SkyResolution256 = 256,
         SkyResolution512 = 512,
         SkyResolution1024 = 1024,
-        // TODO: Anything above 1024 cause a crash in Unity...
-        //SkyResolution2048 = 2048,
-        //SkyResolution4096 = 4096
+        SkyResolution2048 = 2048,
+        SkyResolution4096 = 4096
     }
 
     public enum EnvironementUpdateMode