c8d/list: Remove outdated TODO

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

daemon/containerd/image_list.go

@@ -59,7 +59,6 @@ func (r byCreated) Less(i, j int) bool { return r[i].Created < r[j].Created }
 
 // Images returns a filtered list of images.
 //
-// TODO(thaJeztah): implement opts.ContainerCount (used for docker system df); see https://github.com/moby/moby/issues/43853
 // TODO(thaJeztah): verify behavior of `RepoDigests` and `RepoTags` for images without (untagged) or multiple tags; see https://github.com/moby/moby/issues/43861
 // TODO(thaJeztah): verify "Size" vs "VirtualSize" in images; see https://github.com/moby/moby/issues/43862
 func (i *ImageService) Images(ctx context.Context, opts imagetypes.ListOptions) ([]*imagetypes.Summary, error) {