perf(argocd): turning on selective sync

https://argo-cd.readthedocs.io/en/stable/user-guide/sync-options/#selective-sync

Currently when syncing using auto sync ArgoCD applies every object in the application.
For applications containing thousands of objects this takes quite a long time and puts undue pressure on the api server.
Turning on selective sync option which will sync only out-of-sync resources.

bootstrap/root/templates/stack.yaml

@@ -36,4 +36,5 @@ spec:
             maxDuration: 16m
         syncOptions:
           - CreateNamespace=true
+          - ApplyOutOfSyncOnly=true
 {{- end }}