fix(k8s-helm): get really latest helm chart version
fix(k8s-helm): get really latest helm chart version

Before we were taking latest value from helm versions list,
but it sorts it as strings, not versions.
For example, according to Helm 'v8' is newer than 'v10' which is false.
So, sort available versions correctly and pick up really latest one.

scylladb/scylla-longevity-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests