argocd: update dependency argoproj/argo-cd to v3.1.8

Author: renovate[bot]

argocd/kustomization.yaml

@@ -2,7 +2,7 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 namespace: argocd
 resources:
-  - github.com/argoproj/argo-cd/manifests/cluster-install?ref=03c4ad854c1e6d922a121cd40f505d9bc6e402da # tag=v3.1.0
+  - github.com/argoproj/argo-cd/manifests/cluster-install?ref=becb020064fe9be5381bf6e5818ff8587ca8f377 # tag=v3.1.8
   - ingress.yaml
   - argo-cd-service-monitor.yaml
   - deploy-key.yaml