task-maui-contents-runtime: Remove parted

It doesn't include the development files. We'll build it with ostbuild.
task-maui-contents-devel: Add parted dependencies

In order to build parted with ostbuild we need to install bc and gettext
on the devel base image.
openssh: Add systemd units to the files

Let's see if this works because now the openssh package doesn't get rebuilt
hence we don't have our additions.