Make multisetup-latency.yml independent on multisetup-netsplit.yml

It would be good to be able to configure only network latency, but it is not possible, because ansible playbook multisetup-latency.yml seems to depend on some actions performed by multisetup-netsplit.yml. If it is launched only the multisetup-latency.yml playbook, it fails like this:

2023-03-20 17:53:20  fatal: [osd-3.example.com]: FAILED! => {"changed": false, "msg": "Unable to start service network-latency: Job for network-latency.service failed because of unavailable resources or another system error.\nSee \"systemctl status network-latency.service\" and \"journalctl -xe\" for details.\n"}