partition_version: Make return type of versions() explicit
partition_version: Make return type of versions() explicit

duarten/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla