Merge branch '7683-review-apps-ephemeral-ip-dns' into 'master'

CI/review_apps: Make use of external-dns and ephemeral IPs

Closes #7683

See merge request gitlab-org/gitlab-ee!7443

scripts/review_apps/review-apps.sh

@@ -128,10 +128,10 @@ HELM_CMD=$(cat << EOF
     --set releaseOverride="$CI_ENVIRONMENT_SLUG" \
     --set global.hosts.hostSuffix="$HOST_SUFFIX" \
     --set global.hosts.domain="$REVIEW_APPS_DOMAIN" \
-    --set global.hosts.externalIP="$REVIEW_APPS_DOMAIN_IP" \
     --set certmanager.install=false \
     --set global.ingress.configureCertmanager=false \
     --set global.ingress.tls.secretName=tls-cert \
+    --set global.ingress.annotations."external-dns\.alpha\.kubernetes\.io/ttl"="10"
     --set gitlab.unicorn.resources.requests.cpu=200m \
     --set gitlab.sidekiq.resources.requests.cpu=100m \
     --set gitlab.gitlab-shell.resources.requests.cpu=100m \