Update Helm release cert-manager to v1.18.0

Author: renovate[bot]

cert-manager/garden.yml

@@ -3,7 +3,7 @@ type: helm
 name: cert-manager
 repo: https://charts.jetstack.io
 chart: cert-manager
-version: v1.11.1
+version: v1.18.0
 namespace: cert-manager
 values:
   installCRDs: true