Fix a copy-paste bug

ScriptableRenderPipeline/HDRenderPipeline/Lighting/LightLoop/LightLoop.cs

             lightData.right = light.light.transform.right;
 
             lightDimensions.x = additionalLightData.shapeLength;
-            lightDimensions.x = additionalLightData.shapeWidth;
+            lightDimensions.y = additionalLightData.shapeWidth;
             lightDimensions.z = light.range;
 
             if (lightData.lightType == GPULightType.ProjectorBox)