Load balancers are not zone redundant and can't be configured as such

[jhixson74]

/kind bug

What steps did you take and what happened:
CAPZ does not expose availability zones in the LoadBalancerSpec. I am using CAPZ to provision a cluster by filling out an AzureClusterSpec. The cluster is provisioned correctly. VM's are zone redundant. Internal API load balancer is not zone redundant.

What did you expect to happen:
I expect the internal load balancer to be zone redundant. I expect to be able to configure this via the LoadBalancerSpec struct.

Anything else you would like to add:
Is this intentional? Are there any plans to support this in the future?

Environment:

• Red Hat Open Shift 4.20
• cluster-api-provider-azure version: v1.19.3
• Kubernetes version: k8s.io/client-go v0.32.1
• OS: Fedora 42