[Bug]: network structs do not include/parse vpc network data

### Expected Behavior

Parsing metadata of linodes using next generation interfaces should include the vpc network information.

### Actual Behavior

The vpc fields and addresses are silently dropped.

### Steps to Reproduce

```console
$ curl -fsSH 'Accept: application/json' -H "Metadata-Token: $TOKEN" http://169.254.169.254/v1/network | jq
{
"interfaces": [
{
"id": 123456,
"purpose": "vpc",
"label": null,
"ipam_address": null,
"vpc": {
"id": 123456,
"label": "vpc",
"subnet": {
"id": 123456,
"label": "subnet",
"ipv4": {
"subnet_range": "10.239.x.x/20",
"instance_address": "10.239.x.x/32",
"nat_1_1": "172.234.x.x/32",
"instance_ranges": []
},
"ipv6": null
}
}
}
],
"ipv4": {
"public": [
"172.234.x.x/32"
],
"private": [],
"shared": [],
"vpc": [
"10.239.x.x/32"
]
},
"ipv6": {
"slaac": null,
"ranges": [],
"link_local": null,
"shared_ranges": [],
"vpc": []
}
}
```

### Error Output

https://github.com/siderolabs/talos/issues/13578