feat: Upgrade Keycloak to v26.4.0 (#4402)

Author: aledegano

helm-chart/renku/requirements.yaml

@@ -4,7 +4,7 @@ dependencies:
     repository: "oci://harbor.renkulab.io/bitnami-mirror"
     condition: postgresql.enabled
   - name: keycloakx
-    version: 5.0.0
+    version: 7.1.4
     repository: "https://codecentric.github.io/helm-charts"
     condition: keycloakx.enabled
   - name: redis