chore(deps): update helm chart authentik to v2026.8.3

apps/templates/authentik-helm.yaml

@@ -16,7 +16,7 @@ spec:
   sources:
     - chart: authentik
       repoURL: https://charts.goauthentik.io
-      targetRevision: 2026.2.1
+      targetRevision: 2026.8.3
       helm:
         values: |
           authentik:

apps/templates/cert-manager-helm.yaml

@@ -12,7 +12,7 @@ spec:
   project: default
   source:
     repoURL: https://charts.jetstack.io
-    targetRevision: v1.21.1
+    targetRevision: v1.15.5
     chart: cert-manager
     helm:
       parameters: