alerting: return err when SetAlertState fails to save to sql (#18216)
alerting: return err when SetAlertState fails to save to sql (#18216)

fix duplicate alert states when the alert fails to save to the database.
fixes #18176

grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana