bootstrap-kind: clear DNS search domains in kind config

Podman injects "dns.podman" into node resolv.conf, which leaks
into pod DNS config. CoreDNS cannot resolve this domain, causing
8s timeouts per lookup and killing pods that rely on fast DNS
during init (e.g. zookeeper).

Author: delthas

.github/scripts/end2end/bootstrap-kind.sh

@@ -25,6 +25,8 @@ bootstrap_kind() {
     cat > config.yaml << EOF
 kind: Cluster
 apiVersion: kind.x-k8s.io/v1alpha4
+networking:
+  dnsSearch: []
 nodes:
 - role: control-plane
   image: ${NODE_IMAGE}