Compatibility with Netbox 4.2

[jmcguir]

Due to the scope changes on clusters the netbox plugin won't work with 4.2

https://netboxlabs.com/docs/netbox/en/stable/release-notes/version-4.2/

These two sections will need an upgrade to support 4.2:

1. https://github.com/vatesfr/xen-orchestra/blob/3e69d4c84b2e18c00aebf5362fa7baa16cd30043/packages/xo-server-netbox/src/index.js#L495C1-L495C77

2. xen-orchestra/packages/xo-server-netbox/src/index.js

   Line 566 in 3e69d4c

   site: nbVm.site == null ? nbVm.site : nbVm.site.id,

this is what site looks like now on a cluster:

 "scope_type": "dcim.site",
    "scope_id": 5121,
    "scope": {
        "id": 5121,
        "url": "https://netbox.localhost.net/api/dcim/sites/5121/",
        "display": "6464",
        "name": "6464",
        "slug": "site_6464",
        "description": "Paris"
    },