feat(sso): introduce argocd sso config

otc/observability.t09.de/stacks/core/argocd/values.yaml

@@ -5,6 +5,20 @@ configs:
   params:
     server.insecure: true
   cm:
+    oidc.config: |
+      name: FORGEJO
+      issuer: https://dex.observability.t09.de
+      clientID: controller-argocd-dex
+      clientSecret: $dex-argo-client:clientSecret
+      requestedIDTokenClaims:
+        groups:
+          - DevFW
+        essential: true
+      requestedScopes:
+      - openid
+      - profile
+      - email
+      - groups
     application.resourceTrackingMethod: annotation
     timeout.reconciliation: 60s
     resource.exclusions: |