sci-libs/armadillo: Version bump

Package-Manager: portage-2.2.8-prefix
sci-libs/armadillo: add use flag description

Package-Manager: portage-2.2.8-prefix
sci-libs/armadillo: removed int64 flag, it is only for revdep at compile time

Package-Manager: portage-2.2.8-prefix
sci-libs/mlpack: Version bump

Package-Manager: portage-2.2.8-prefix