chore(deps): update helm release external-dns to v1.15.1

Author: renovate[bot]

kubernetes/apps/external-dns/Chart.yaml

@@ -6,6 +6,6 @@ version: 0.1.1
 dependencies:
   - name: external-dns
     repository: https://kubernetes-sigs.github.io/external-dns
-    version: 1.14.4
+    version: 1.15.1
     alias: external-dns