When inside the openstackdataplanenodeset CR a user doesn't set the ansibleHost to an IP address of each compute node and at the same time IP set doesn't exist, scraping of Node Exporter metrics fails with TLS errors:

2024-11-18T21:05:52.734089145Z ts=2024-11-18T21:05:52.733996025Z caller=stdlib.go:105 caller=server.go:3212 msg="http: TLS handshake error from <IP address>:53884: EOF" 

The reason of the issue is, that node exporter and kepler certificates are generated only for the compute node IP addresses, not for the compute node hostnames. When the ansibleHost isn't explicitly set in the openstackdataplanenodeset CR, the openstack-operator sets the ansible_host variable in the dataplane inventory CR to a hostname of the compute node. The ansible_host variable is then read by the telemetry_operator and used for ScrapeConfigs. So this way Prometheus gets configured to scrape the Node Exporter by using a hostname, while TLS certificates are created only for IP addresses.

We should be generating Node Exporter and Kepler certificates so that they also work with hostnames.

We need to add `- dnsnames` under https://github.com/openstack-k8s-operators/openstack-operator/blob/main/config/services/dataplane_v1beta1_openstackdataplaneservice_telemetry.yaml#L13
ditto for kepler.