fix: opensearch连接的空索引查询_doc的id最大值转换问题

src/service/alert.go

@@ -686,7 +686,7 @@ func (a *AlertSvc) GetIndexMaxID(indexName ...string) (maxId int, err error) {
 	aggregations := responseMap["aggregations"].(map[string]interface{})
 	maxIDAgg := aggregations["max_id"].(map[string]interface{})
 	maxIDValue := maxIDAgg["value"]
-	maxId = int(maxIDValue.(float64))
+	maxId = cast.ToInt(maxIDValue)
 
 	return maxId, nil
 }