add comment to regression test
As suggested by add a comment to the regression test
of to better document the context.
@@ -541,6 +541,8 @@ json-file | f
run_podman inspect $IMAGE --format "{{.ID}}"
imageID="$output"
+ # prior to #8623 `podman run` would error out on untagged images with:
+ # Error: both RootfsImageName and RootfsImageID must be set if either is set: invalid argument
run_podman untag $IMAGE
run_podman run --rm $imageID ls
