Support propertly a layer2 subnet with dual stack by enforcing tha the "ips" argument at the "v1.multus-cni.io/default-network" annotation follow the ip family from the layer2 network that's it:

• single stack ipv4 -> it should have just one ipv4 address
• dual stack -> it should have a pair of addresses one ipv4 and the other ipv6
• single stack ipv6 -> it should have just one ipv6 address