fix(artifacts pipeline): remove disableConcurrentBuilds()
fix(artifacts pipeline): remove disableConcurrentBuilds()

since we need to run the artifact ami test in parallel,
we are removing `disableConcurrentBuilds()` from the pipeline

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