Update Helm release cert-manager to v1.20.3

Author: renovate[bot]

infrastructure/controllers/cert-manager/kustomization.yaml

@@ -8,7 +8,7 @@ resources:
 helmCharts:
   - name: cert-manager
     repo: https://charts.jetstack.io
-    version: v1.20.2
+    version: v1.20.3
     releaseName: cert-manager
     namespace: cert-manager
     valuesFile: values.yaml