Essentially, Workspace (and Screen) types were defined as not localizable. In previous code it happended to work by mere chance (code path taken in `BKE_library_make_local` was conviniently skipping the call to `BKE_lib_id_make_local` in that case, hence not checking for `IDTYPE_FLAGS_NO_MAKELOCAL` flag of the localized ID type). This is a total abuse of this IDType flag, for now removing it. That specific case (IDtype appendable but nor linkable) requires its own proper flag, this will be tackled in a later commit. Issue introduced in rB3be5ce4aad5e.