fix(webhook) exclude Helm Secrets

Helm charts with webhooks that handle Secrets run into an issue that
prevents changes after an action that enables the webhook:
helm/helm#10023

Because Helm's Secret for release information is subject to the webhook,
Kubernetes will attempt to validate it, likely before the webhook
service comes online (because Helm just created the Pod that will
provide it). If the service is not online, validation fails, and Helm
cannot update its Secret to mark the release status, usually leaving it
stuck in a pending state that blocks future interactions.

This change excludes Helm Secrets from our validation, because we have
no need to validate them.

charts/kong/templates/admission-webhook.yaml

@@ -34,6 +34,9 @@ metadata:
     {{- include "kong.metaLabels" . | nindent 4 }}
 webhooks:
 - name: validations.kong.konghq.com
+  objectSelector:
+    matchLabels:
+      owner: !helm
   failurePolicy: {{ .Values.ingressController.admissionWebhook.failurePolicy }}
   sideEffects: None
   admissionReviewVersions: ["v1beta1"]