Bug: Properties file fails to create if no columns defined in existing yml

[rubyDoomsday]

Bug

I am using this script to migrate a bunch of single file (schema.yml) properties to individiual properties files (1 per model). Many of the declarations in the schema.yml do not include any column details/tests. After running dbt-invoke properites.migrate --models <mode-name> the declaration is removed from schema.yml and a new <model_name>.yml is created successfully. However, if I follow up with dbt-invoke properties.update --models <model-name> the script produces the error:

dbt-invoke |   INFO   | Searching for matching resources...
dbt-invoke |   INFO   | Found 1 matching resources in dbt project [REDACTED]
dbt-invoke |   INFO   |   [START] Resource 1 of 1, models/<model-name>.sql
dbt-invoke |  ERROR   | [FAILURE] Resource 1 of 1, models/<model-name>.sql
dbt-invoke |  ERROR   | Tracebacks for all failures:

Resource 1 of 1, models/LEVEL_02_MODELS/L02_API_AFFILIATE_DECLINES.SQL
Traceback (most recent call last):
  File ".../python3.11/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../python3.11/site-packages/dbt_invoke/properties.py", line 714, in _create_property_file
    property_file_dict = _structure_property_file_dict(
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../python3.11/site-packages/dbt_invoke/properties.py", line 818, in _structure_property_file_dict
    for item in property_file_dict[resource_type_plural][0]['columns']
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File ".../python3.11/site-packages/ruamel/yaml/comments.py", line 853, in __getitem__
    return ordereddict.__getitem__(self, key)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
KeyError: 'columns'

dbt-invoke |   INFO   |    [DONE] Total: 1, Successes: 0, Failures: 1

Workaround

Updating the migrated .yml poperties file to contain a columns section resolves the issue and the properties file can be created successfully. It doesn't require a column name that is relevant to the table/view that it describes, only that the yml tier exists. Note that a column name most be present for the yml to parse correctly. Example

version: 2
models:
- name: <model-name>
  description: 'some description that was migrated from the single schema.yml'
  columns:
  - name: ID

Running dbt-invoke properties.update --models <mode-name> after adding columns: -name: ID:

dbt-invoke |   INFO   | Searching for matching resources...
dbt-invoke |   INFO   | Found 1 matching resources in dbt project [REDACTED]
dbt-invoke |   INFO   |   [START] Resource 1 of 1, models/<model-name>.sql
dbt-invoke |   INFO   | [SUCCESS] Resource 1 of 1, models/<model-name>.sql
dbt-invoke |   INFO   |    [DONE] Total: 1, Successes: 1, Failures: 0