RelatedObjectDoesNotExist is raised when the form contains options to set multiple objects

[abhi1693]

NetBox version

v3.5.0-beta2

Python version

3.10

Steps to Reproduce

This is found via a plugin for a form written at https://github.com/Onemind-Services-LLC/netbox-device-lifecycle-mgmt/blob/dev/netbox_device_lifecycle_mgmt/forms/model_forms.py#L31

When a user selected device_type and module_type fields together, the page crashes

Expected Behavior

Page should not crash

When I apply the following patch, the page works as expected

diff --git a/netbox/netbox/models/__init__.py b/netbox/netbox/models/__init__.py
index fe25bb837..c0f679e4f 100644
--- a/netbox/netbox/models/__init__.py
+++ b/netbox/netbox/models/__init__.py
@@ -67,8 +67,8 @@ class NetBoxModel(CloningMixin, NetBoxFeatureSet, models.Model):
 
         for field in self._meta.get_fields():
             if isinstance(field, GenericForeignKey):
-                ct_value = getattr(self, field.ct_field)
-                fk_value = getattr(self, field.fk_field)
+                ct_value = getattr(self, field.ct_field, None)
+                fk_value = getattr(self, field.fk_field, None)
 
                 if ct_value is None and fk_value is not None:
                     raise ValidationError({

Observed Behavior

Internal Server Error: /plugins/device-lcm/hardware-notices/add/
Traceback (most recent call last):
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/core/handlers/exception.py", line 56, in inner
    response = get_response(request)
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/views/generic/base.py", line 103, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/asaharan/PycharmProjects/netbox/netbox/netbox/views/generic/object_views.py", line 167, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/home/asaharan/PycharmProjects/netbox/netbox/netbox/views/generic/base.py", line 26, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/home/asaharan/PycharmProjects/netbox/netbox/utilities/views.py", line 99, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/views/generic/base.py", line 142, in dispatch
    return handler(request, *args, **kwargs)
  File "/home/asaharan/PycharmProjects/netbox/netbox/netbox/views/generic/object_views.py", line 255, in post
    if form.is_valid():
  File "/home/asaharan/PycharmProjects/netbox/netbox/utilities/forms/mixins.py", line 52, in is_valid
    is_valid = super().is_valid()
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/forms/forms.py", line 205, in is_valid
    return self.is_bound and not self.errors
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/forms/forms.py", line 200, in errors
    self.full_clean()
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/forms/forms.py", line 439, in full_clean
    self._post_clean()
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/forms/models.py", line 492, in _post_clean
    self.instance.full_clean(exclude=exclude, validate_unique=False)
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/db/models/base.py", line 1455, in full_clean
    self.clean()
  File "/home/asaharan/PycharmProjects/netbox/netbox/netbox/models/__init__.py", line 71, in clean
    ct_value = getattr(self, field.ct_field)
  File "/home/asaharan/PycharmProjects/netbox/venv/lib/python3.10/site-packages/django/db/models/fields/related_descriptors.py", line 217, in __get__
    raise self.RelatedObjectDoesNotExist(
netbox_device_lifecycle_mgmt.models.hardware.HardwareNotice.object_type.RelatedObjectDoesNotExist: HardwareNotice has no object_type.

[kkthxbye-code]

Just to add some context, it's caused #11550 which was merged in 3.4.8, so I would guess this doesn't only effect 3.5.