delete Watchdog of alert rule

jsonnet/kube-prometheus/alerts/general.libsonnet

@@ -15,22 +15,6 @@
               severity: 'warning',
             },
           },
-          {
-            alert: 'Watchdog',
-            annotations: {
-              message: |||
-                This is an alert meant to ensure that the entire alerting pipeline is functional.
-                This alert is always firing, therefore it should always be firing in Alertmanager
-                and always fire against a receiver. There are integrations with various notification
-                mechanisms that send a notification when this alert is not firing. For example the
-                "DeadMansSnitch" integration in PagerDuty.
-              |||,
-            },
-            expr: 'vector(1)',
-            labels: {
-              severity: 'none',
-            },
-          },
         ],
       },
     ],