AttributeError in running Generate FW Config via Capirca job

[glennmatthews]

Environment

• Python version: 3.11
• Nautobot version: 2.1.1
• nautobot-firewall-models version: 2.0.3

Expected Behavior

Job to run to completion or fail with a user-friendly explanation.

Observed Behavior

Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 581, in get_or_create
    return self.get(**kwargs), False
           ^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 435, in get
    raise self.model.DoesNotExist(
nautobot_firewall_models.models.capirca_policy.CapircaPolicy.DoesNotExist: CapircaPolicy matching query does not exist.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/celery/app/trace.py", line 477, in trace_task
    R = retval = fun(*args, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/nautobot/extras/jobs.py", line 152, in __call__
    return self.run(*args, **deserialized_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/nautobot/.local/lib/python3.11/site-packages/nautobot_firewall_models/jobs.py", line 51, in run
    CapircaPolicy.objects.update_or_create(device=device_obj)
  File "/usr/local/lib/python3.11/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 608, in update_or_create
    obj, created = self.select_for_update().get_or_create(defaults, **kwargs)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 588, in get_or_create
    return self.create(**params), True
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/db/models/query.py", line 453, in create
    obj.save(force_insert=True, using=self.db)
  File "/opt/nautobot/.local/lib/python3.11/site-packages/nautobot_firewall_models/models/capirca_policy.py", line 54, in save
    cap_obj.get_all_capirca_cfg()
  File "/opt/nautobot/.local/lib/python3.11/site-packages/nautobot_firewall_models/utils/capirca.py", line 600, in get_all_capirca_cfg
    self.validate_policy_data()
  File "/opt/nautobot/.local/lib/python3.11/site-packages/nautobot_firewall_models/utils/capirca.py", line 356, in validate_policy_data
    "from-zone": rule["source_zone"].name,
                 ^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'name'

Steps to Reproduce

1. Create a Policy Rule with no source_zone or destination_zone value
2. Attach the policy rule to a device
3. Run Generate FW Config via Capirca job with the given device