OpenStack cluster-API provider should use the CloudCredential capability for its CredentialsRequest

Description of problem:

On TechPreviewNoUpgrade clusters with the CloudCredential capability disabled, the cluster will fail to install as the cluster-version operator fails to push the openstack-cloud-credentials CredentialsRequest into the cluster, because the CloudCredential capability must be enabled to get the CredentialsRequest CRD.

How reproducible:

Untested, but expected to be every time.

Steps to Reproduce:

1. Try and install a cluster with TechPreviewNoUpgrade and CloudCredential disabled.

Actual results:

Install fails.

Expected results:

Install succeeds. The CVO does not attempt to push any CloudCredential into the cluster.