[test][facet][1pnc] do not require UMFPack
The facet-couling 1pnc tests were using UMFPack, although they also work fine using iterative solvers. This merge request removes this dependency, which was also not checked for using a CMAKE_GUARD.
The facet-couling 1pnc tests were using UMFPack, although they also work fine using iterative solvers. This merge request removes this dependency, which was also not checked for using a CMAKE_GUARD.