CoreDNS `k8s_external` headless AXFR can emit an empty transfer batch that panics the `transfer` plugin

{
                    "vendor": "coredns",
                    "product": "coredns",
                    "versions": [
                        {
                            "version": ">= 1.9.4, < 1.14.5",
                            "status": "affected"
                        }
                    ]
                }