Merge pull request #8407 from ieQu1/doc-cluster-singleton

docs(emqx_connector): Remove mentions of cluster_singleton

apps/emqx_connector/i18n/emqx_connector_mqtt_schema.conf

@@ -2,11 +2,8 @@ emqx_connector_mqtt_schema {
     mode {
         desc {
           en: """
-The mode of the MQTT Bridge. Can be one of 'cluster_singleton' or 'cluster_shareload'</br>
+The mode of the MQTT Bridge.</br>
 
-- cluster_singleton: create a unique MQTT connection within the emqx cluster.</br>
-In 'cluster_singleton' node, all messages toward the remote broker go through the same
-MQTT connection.</br>
 - cluster_shareload: create an MQTT connection on each node in the emqx cluster.</br>
 In 'cluster_shareload' mode, the incoming load from the remote broker is shared by
 using shared subscription.</br>
@@ -15,10 +12,7 @@ clientid conflicts between different nodes. And we can only use shared subscript
 topic filters for 'remote_topic' of ingress connections.
 """
           zh: """
-MQTT 桥的模式。 可用的类型有“cluster_singleton”，“cluster_shareload”。</br>
-
-- cluster_singleton：在 emqx 集群内创建唯一的 MQTT 连接。</br>
-在“cluster_singleton”节点中，所有发往远程代理的消息都通过相同的MQTT 连接。</br>
+MQTT 桥的模式。 </br>
 
 - cluster_shareload：在 emqx 集群的每个节点上创建一个 MQTT 连接。</br>
 在“cluster_shareload”模式下，来自远程代理的传入负载通过共享订阅的方式接收。</br>