docs(alerting): add recommendation to reduce duplicated DatasourceError alerts (#104679)

docs(alerting): add recommendation to reduce `DatasourceError` alerts

docs/sources/alerting/fundamentals/alert-rule-evaluation/state-and-health.md

@@ -39,6 +39,11 @@ refs:
       destination: /docs/grafana/<GRAFANA_VERSION>/alerting/fundamentals/notifications/
     - pattern: /docs/grafana-cloud/
       destination: /docs/grafana-cloud/alerting-and-irm/alerting/fundamentals/notifications/
+  notification-policies:
+    - pattern: /docs/grafana/
+      destination: /docs/grafana/<GRAFANA_VERSION>/alerting/fundamentals/notifications/notification-policies/
+    - pattern: /docs/grafana-cloud/
+      destination: /docs/grafana-cloud/alerting-and-irm/alerting/fundamentals/notifications/notification-policies/
 ---
 
 # State and health of alerts
@@ -131,6 +136,8 @@ To minimize the number of **No Data** or **Error** state alerts received, try th
 
 1. Change the default [evaluation time out](https://grafana.com/docs/grafana/latest/setup-grafana/configure-grafana/#evaluation_timeout). The default is set at 30 seconds. To increase the default evaluation timeout, open a support ticket from the [Cloud Portal](https://grafana.com/docs/grafana-cloud/account-management/support/#grafana-cloud-support-options). Note that this should be a last resort, because it may affect the performance of all alert rules and cause missed evaluations if the timeout is too long.
 
+1. To reduce multiple notifications from **Error** alerts, define a [notification policy](ref:notification-policies) to handle all related alerts with `alertname=DatasourceError`, and filter and group errors from the same data source using the `datasource_uid` label.
+
 ### Keep last state
 
 The "Keep Last State" option helps mitigate temporary data source issues, preventing alerts from unintentionally firing, resolving, and re-firing.