Alerting: Skip query cache for alert queries (#39010)

pkg/services/alerting/conditions/query.go

@@ -269,7 +269,8 @@ func (c *QueryCondition) getRequestForAlertRule(datasource *models.DataSource, t
 			},
 		},
 		Headers: map[string]string{
-			"FromAlert": "true",
+			"FromAlert":    "true",
+			"X-Cache-Skip": "true",
 		},
 		Debug: debug,
 	}

pkg/services/ngalert/eval/eval.go

@@ -124,7 +124,8 @@ func GetExprRequest(ctx AlertExecCtx, data []models.AlertQuery, now time.Time) (
 		OrgId: ctx.OrgID,
 		Headers: map[string]string{
 			// Some data sources check this in query method as sometimes alerting needs special considerations.
-			"FromAlert": "true",
+			"FromAlert":    "true",
+			"X-Cache-Skip": "true",
 		},
 	}