in pkg/clusters/clusters.go [171:175]
func (m *clusterMigrator) upgradeNodePools(ctx context.Context) error {
log.Infof("Initiate NodePool upgrades for Cluster %s", m.ResourcePath())
sem := make(chan struct{}, m.opts.ConcurrentNodePools)
return migrate.Migrate(ctx, sem, m.children...)
}