bumped cache version for landscape (#2515)

## What does this PR change?
see title 

## How to test the changes?

check if [#2190](#2190) is fixed

Explorer/Assets/DCL/Landscape/TerrainGenerator.cs

@@ -16,7 +16,6 @@
 using Unity.Jobs;
 using Unity.Mathematics;
 using UnityEngine;
-using UnityEngine.Profiling;
 using Utility;
 using JobHandle = Unity.Jobs.JobHandle;
 
@@ -28,7 +27,7 @@ public class TerrainGenerator : IDisposable, IContainParcel
         private const float ROOT_VERTICAL_SHIFT = -0.01f; // fix for not clipping with scene (potential) floor
 
         // increment this number if we want to force the users to generate a new terrain cache
-        private const int CACHE_VERSION = 7;
+        private const int CACHE_VERSION = 8;
 
         private const float PROGRESS_COUNTER_EMPTY_PARCEL_DATA = 0.1f;
         private const float PROGRESS_COUNTER_TERRAIN_DATA = 0.3f;