Fix: EEVEE-Next: NaN in surfel lighting with area lights

This fix broken lighting in volume probe baking if
any area light is present in the scene.

source/blender/draw/engines/eevee_next/shaders/eevee_surfel_light_comp.glsl

@@ -33,6 +33,8 @@ void main()
                                                    surfel.albedo_front;
   }
 
+  V = -surfel.normal;
+  Ng = -surfel.normal;
   stack.cl[0].N = -surfel.normal;
   light_eval(stack, P, Ng, V);