fix: remove alerting config from heartbeat receiver

Author: henrywhitaker3

argo/cluster/monitoring/kube-prometheus-stack/chart/values.yaml

@@ -20,9 +20,6 @@ alertmanager:
     receivers:
       - name: "null"
       - name: heartbeat
-        webhook_configs:
-          - url: http://uptime-kuma.monitoring.svc:3001/api/push/YiR8xNCHCS?status=up&msg=OK&ping=/alertmanager
-            send_resolved: true
       - name: discord
         slack_configs:
           - api_url_file: /etc/alertmanager/secrets/alertmanager-secrets/slack