Fix #133367: Use BKE_unit_value_as_string_scaled for ruler gizmo

`BKE_unit_value_as_string` was modified in e949ff7334
to include a `BKE_unit_value_as_string_scaled` version, some places on
the interface needs to use the scaled version to show the string, this
includes ruler gizmo length text.

Pull Request: https://projects.blender.org/blender/blender/pulls/133373

source/blender/editors/space_view3d/view3d_gizmo_ruler.cc

@@ -215,7 +215,8 @@ static void ruler_item_as_string(
       BLI_snprintf(numstr, numstr_size, "%.*f", prec, ruler_len);
     }
     else {
-      BKE_unit_value_as_string(numstr, numstr_size, ruler_len, prec, B_UNIT_LENGTH, unit, false);
+      BKE_unit_value_as_string_scaled(
+          numstr, numstr_size, ruler_len, prec, B_UNIT_LENGTH, unit, false);
     }
   }
 }