Image cleanup broken after failed import

[osfrickler]

When an image import (upload) fails, the properties for the image have not yet been set when the manager tries to clean up the image, leading to a traceback like

│ /usr/local/lib/python3.12/site-packages/openstack_image_manager/main.py:1015 in manage_outdated_images                                                       │                                                                                                                 
│                                                                                                                                                              │                                                                                                                 
│   1012 │   │   │   logger.info(f"Processing image '{image}' (removal candidate)")                                                                            │                                                                                                                 
│   1013 │   │   │                                                                                                                                             │                                                                                                                 
│   1014 │   │   │   cloud_image = cloud_images[image]                                                                                                         │                                                                                                                 
│ ❱ 1015 │   │   │   image_name = cloud_image.properties["image_description"]                                                                                  │                                                                                                                 
│   1016 │   │   │                                                                                                                                             │                                                                                                                 
│   1017 │   │   │   if image_name not in images:                                                                                                              │                                                                                                                 
│   1018 │   │   │   │   logger.warning(                                                                                                                       │                                                                                                                 
│                                                                                                                                                              │
...
KeyError: 'image_description'