feat(helm): update chart external-secrets to 0.15.1

.github/workflows/renovate.yaml

@@ -10,7 +10,7 @@ on:
 jobs:
   renovate:
     runs-on: ubuntu-latest
-    container: ghcr.io/renovatebot/renovate:39.240.1
+    container: ghcr.io/renovatebot/renovate:39.220.3
     steps:
       - uses: actions/checkout@v4
       - run: renovate

kubernetes/apps/external-secrets/app/helmrelease.yaml

@@ -8,7 +8,7 @@ spec:
   chart:
     spec:
       chart: external-secrets
-      version: 0.16.0
+      version: 0.15.1
       sourceRef:
         kind: HelmRepository
         name: external-secrets