Fix `container image prune` to actually remove images, add `-a` flag support, and bump cz to 0.15.0 by realrajaryan · Pull Request #909

Fix `container image prune` to actually remove images, add `-a` flag support, and bump cz to 0.15.0 by realrajaryan · Pull Request #909 · apple/container

saehejkang pushed a commit to saehejkang/container that referenced this pull request

…support, and bump cz to 0.15.0 (apple#909)

- Fixes apple#901.

## Type of Change
- [x] Bug fix
- [x] New feature  
- [ ] Breaking change
- [ ] Documentation update

## Motivation and Context
Previously `container image prune` called `ImageStore.prune()` (renamed
to `cleanupOrphanedBlobs()` in cz 0.15.0) which only removed orphaned
content blobs and never actually removed images.

This PR fixes that behavior so `container image prune` removes dangling
images by default, and with `-a` removes all unused images, not just
dangling ones.

## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [ ] Added/updated docs