Description of Problem

 Duplicated notifications based on argocd-notifications-controller replica count 

Additional Info

NA

Problem Reproduction

• Install OpenShift GitOps (Any supported version) 
• Enable notifications in ArgoCD CR
• Configure webhook service and use the `oncePer` field under Trigger.
• Increase the replicas of notifications-controller to 2. 
• Every time the application would sync, it triggers notifications twice. 

Reproducibility

Always

Prerequisites/Environment

OCP 4.16

Expected Results

 Operator should throw an error for notifications-controller replicas if multiple replicas are not supported currently. 

Actual Results

The notification is sent as per the notification-controller replica count and there is no indication that multiple replicas are not supported. 

Workaround (If Possible)

Reduce the replica count to 1.