Merge pull request kubernetes-sigs#2852 from k8s-infra-cherrypick-robot/cherry-pick-2851-to-release-0.12

[release-0.12] 🐛 Remove invalid kustomizeconfig from config/webhook

Author: k8s-ci-robot

config/webhook/kustomization.yaml

@@ -1,6 +1,3 @@
 resources:
 - manifests.yaml
 - service.yaml
-
-configurations:
-- kustomizeconfig.yaml