This is a clone of issue OCPBUGS-37681. The following is the description of the original issue:
—
The tests:

• "The OpenStack platform creates Control plane nodes in a server group"
• "The OpenStack platform creates Worker nodes in a server group"

fail in a UPI cluster because there are no machines in UPI.

$ oc -n openshift-machine-api get machines
No resources found in openshift-machine-api namespace.

$ oc -n openshift-machine-api get machine ostest-2vvxq-master-0 -o json | jq '.spec.providerSpec.value.serverGroupName'
Error from server (NotFound): machines.machine.openshift.io "ostest-2vvxq-master-0" not found

so there is no "machine.openshift.io/machine" annotation in the nodes:

$ oc get nodes ostest-2vvxq-master-0 -o json | jq '.metadata.annotations."machine.openshift.io/machine"'
null

The tests in openstack-test should be skipped when there are no machines.