CI upgrade from 1.2 to 1.3 is broken

This is about the failure in https://gitlab.com/sylva-projects/sylva-core/-/jobs/10823251037#L2922 (☁capo 🚀rke2 🐧suse 🛠ha 🎬sylva-upgrade-from-1.2.1)

I think this is due to !4876 (diffs), which fixed 1.3, but since 1.2 isn't fixed, we try to transition the number of servers from a wrong count in sylva 1.2 to a now-fixed count in sylva 1.3

We discussed it today with @feleouet and, given that we do not have a release-1.2 branch in which to push a backport, we need a different solution. A possible one would be to fix the node_count in ci-deployment-values repo, under deployment-values/1.2.