Visual bugs when built with lto option

Description:

The packaged version of freecad has graphical issues as documented here - https://github.com/FreeCAD/FreeCAD/issues/6698

As noted in my most recent comments on the linked issue, adding the !lto option appears to fix the issue - https://github.com/FreeCAD/FreeCAD/issues/6698#issuecomment-1974989724