IPv6 support for baremetal provider

**What would you like to be added**:
Currently EKS supports IPv6 and Kubernetes also supports IPv6 on it's dual stack mode.
However EKS-A cannot use IPv6.
For example we cannot use IPv6 addresses in [clusterNetwork](https://anywhere.eks.amazonaws.com/docs/getting-started/ports/) or hardware csv:

```
eksctl anywhere create cluster --hardware-csv expt-eksa-mgmt-ipv6-hardware.csv -f expt-eksa-mgmt-ipv6-cluster.yaml
Warning: The recommended number of control plane nodes is 3 or 5
Warning: No configurations provided for worker node groups, pods will be scheduled on control-plane nodes
Error: the cluster config file provided is invalid: the size of pod subnet with mask 64 is smaller than or equal to the size of node subnet with mask 24
```

**Why is this needed**:
Pods and nodes on EKS-A has only IPv4 and they cannot easily communicate with or host IPv6 only system.

Start with the eksctl anywhere create cluster path and the clusterNetwork and hardware CSV validation described in the issue, using the IPv6 example to reproduce the subnet-mask error. Review the linked ports documentation and determine the changes needed for EKS-A to accept IPv6 or dual-stack addresses; done means the example configuration validates without that error.

Written by the indexing model from the issue text.