fix(apps): drop duplicate keycloak-client secret (chart owns it)

The forteapp chart renders Secret/keycloak-client-forte-drop from
auth.registration values (verified: the live secret is tracked by
the forte-drop Application and carries the correct
drop.forteapps.net redirect). The overlay copy gives the secret two
owners — enterprise-apps and forte-drop self-heal against each
other in a sync loop (the Slack spam). Remove the overlay copy;
the chart is the single source.

apps/overlays/upc-dev/forte-drop/kustomization.yaml

@@ -2,6 +2,5 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:
 - forte-drop.yaml
-- keycloak-client-forte-drop.yaml
 - forte-drop-pdb.yaml
 - forte-drop-secrets-sealed.yaml