one fix (#4810)

Co-authored-by: Xin Kai Lee <[email protected]>

Author: simone-silvestri

src/TurbulenceClosures/turbulence_closure_implementations/advective_skew_diffusion.jl

@@ -65,7 +65,7 @@ end
     inactive = peripheral_node(i, j, k, grid, Center(), Face(), Face())
     Sy = ifelse(inactive, zero(grid), Sy)
 
-    return ifelse(bz == 0, zero(grid), - by / bz)
+    return Sy
 end
 
 # tapered slope in x-direction at F, C, F locations