[bot] [main] Automated version update (#2357)

Co-authored-by: Prometheus Operator Bot <prom-op-bot@users.noreply.github.com>

manifests/alertmanager-serviceAccount.yaml

@@ -7,6 +7,6 @@ metadata:
     app.kubernetes.io/instance: main
     app.kubernetes.io/name: alertmanager
     app.kubernetes.io/part-of: kube-prometheus
-    app.kubernetes.io/version: 0.26.0
+    app.kubernetes.io/version: 0.27.0
   name: alertmanager-main
   namespace: monitoring