ImagePruner ability to skip unavailable images

1. Proposed title of this feature request

ImagePruner ability to skip unavailable images

2. What is the nature and description of the request?

ImagePruner is unable to skip unavailable images so it crashes without deleting old images.

3. Why does the customer need this? (List the business requirements here)

ImagePruner doesn't do its job. It should fail with a message that some image doesn't exist but it shouldn't stop deleting. It should always try to do its primary job.

4. How would you like to achieve this?

ImagePruner should fail after it tries to do its main job, which is deleting old images. It seems silly that only one wrong referenced image would stop deleting old images. We really think that this type of behavior should change.

5. Tests for successful implementation.

      A. You have to have some old images in your registry at first

      B. Secondly, create some Deplyoments which refer to image: nginx:latest

     C. By accident, change image property in that Deplyoments into nginx@latest

     D. Run image prune command

    E. Command will failed with message that nginx@latest doesn't exist and it would delete old images