IPAddress with assigned_object_type_id set, but no assigned_object

[sirtux]

Environment

• Python version: 3.9.5
• Nautobot version: 1.1.5

Steps to Reproduce

Unclear, all changes to IP objects are done via API,
and I have no idea what exactly caused this to happen

Expected Behavior

Any IPAddress with assigned_object_type_id set should have an assigned_object

Observed Behavior

>>> foo = IPAddress.objects.get(id='6f06b711-1273-44a1-a2d4-a94a9ce82f36')
>>> pp.pprint(vars(foo))
{   '_custom_field_data': {'ASN': None},
    '_django_version': '3.1.13',
    '_state': <django.db.models.base.ModelState object at 0x7fc6837e1a90>,
    'assigned_object_id': None,
    'assigned_object_type_id': 86,
    'broadcast': '1.1.1.1',
    'created': datetime.date(2021, 11, 30),
    'description': '',
    'dns_name': '',
    'host': '1.1.1.1',
    'id': UUID('6f06b711-1273-44a1-a2d4-a94a9ce82f36'),
    'last_updated': datetime.datetime(2021, 12, 4, 10, 27, 49, 79927, tzinfo=<UTC>),
    'nat_inside_id': None,
    'prefix_length': 32,
    'role': '',
    'status_id': UUID('c0a02630-58a1-478a-aea4-04b084ace732'),
    'tenant_id': UUID('acd560e2-22df-4835-95b3-ef1e00f94ca0'),
    'vrf_id': UUID('4e10b062-971e-44af-97a5-be52f41c86b9')}

[glennmatthews]

It does look like the PUT/PATCH REST API allows assigned_object_type and assigned_object_id to be set as separate fields, and I don't see at a glance any logic in the model clean method that checks that either both are null or both are non-null, so it looks like this should be pretty easy to recreate intentionally.