chore: Update OpenShift GitOps to 1.8

[nastacio]

Closes: #288

Description of changes:

• Update operator version from stable to gitops-1.8

Output of argocd app list command or screenshot of the ArgoCD Application synchronization window showing successful application of changes in this branch.

argocd app list
NAME                                  CLUSTER                         NAMESPACE                PROJECT               STATUS  HEALTH   SYNCPOLICY  CONDITIONS  REPO                                    PATH                                  TARGET
openshift-gitops/argo-app             https://kubernetes.default.svc  openshift-gitops         argocd-control-plane  Synced  Healthy  Auto-Prune  <none>      https://github.com/IBM/cloudpak-gitops  config/argocd                         288-ocp413
openshift-gitops/cp-shared-app        https://kubernetes.default.svc  ibm-cloudpaks            default               Synced  Healthy  Auto-Prune  <none>      https://github.com/IBM/cloudpak-gitops  config/argocd-cloudpaks/cp-shared     288-ocp413
openshift-gitops/cp-shared-operators  https://kubernetes.default.svc  ibm-cloudpaks            default               Synced  Healthy  Auto-Prune  <none>      https://github.com/IBM/cloudpak-gitops  config/cloudpaks/cp-shared/operators  288-ocp413
openshift-gitops/rhacm-app            https://kubernetes.default.svc  open-cluster-management  rhacm-control-plane   Synced  Healthy  Auto-Prune  <none>      https://github.com/IBM/cloudpak-gitops  config/argocd-rhacm                   288-ocp413
openshift-gitops/rhacm-cloudpaks      https://kubernetes.default.svc  open-cluster-management  rhacm-control-plane   Synced  Healthy  Auto        <none>      https://github.com/IBM/cloudpak-gitops  config/rhacm/cloudpaks                288-ocp413
openshift-gitops/rhacm-seeds          https://kubernetes.default.svc  open-cluster-management  rhacm-control-plane   Synced  Healthy  Auto        <none>      https://github.com/IBM/cloudpak-gitops  config/rhacm/seeds                    288-ocp413