Adjust open5gs-latest and osmo-uecups-latest to not hardcode a UID. This
is in preparation for creating a "build" user in
debian-bookworm-obs-latest, like we have it in debian-bookworm-build.
Change-Id: Icaebf46487056cea745805527fdc545d9a1846cd
ping is needed for ttcn3-pgw-test. In the case of osmo-uecups-master
it's available from the parent $DISTRO-build image, but for the -latest
it needs to be installed by the inherited image itself.
Change-Id: Ia1b9124f09203c7dcf6d26dee78b09d5a139a04f
Related: OS#5913