Runner CRD: Add required conversionReviewVersions field (#1259)

Without that field, GKE 1.21 refuses to create the CRD
with an error message that conversionReviewVersions is mandatory.

conversionReviewVersions is a required field when creating apiextensions.k8s.io/v1 custom resource definitions.
Webhooks are required to support at least one ConversionReview version understood by the current and previous API server.

See https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/_print/#webhook-request-and-response

config/crd/patches/webhook_in_runners.yaml

@@ -8,6 +8,7 @@ spec:
   conversion:
     strategy: Webhook
     webhook:
+      conversionReviewVersions: ["v1","v1beta1"]
       clientConfig:
         # this is "\n" used as a placeholder, otherwise it will be rejected by the apiserver for being blank,
         # but we're going to set it later using the cert-manager (or potentially a patch if not using cert-manager)