Dubbo Admin 标签路由功能未生效

- [ ] I have searched the [issues](https://github.com/apache/dubbo-admin/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [REAMDE](https://github.com/apache/dubbo-admin/blob/develop/README.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo Admin version: 0.5.0
* Registry center detail (type and version): nacos1.2.1
* Operating System version: windows
* Java version: jdk1.8
* dubbbo version： dubbo3.1.4

### Steps to reproduce this issue

1. 部署 dubbo admin ，调整 application.properties 配置， 支持 nacos 配置中心和注册中心

如下配置
```
server.port=18879
dubbo.protocol.port=18880
dubbo.application.qos-port=38880
admin.registry.address=nacos://10.32.52.57:8848?username=nacos&password=nacos
admin.config-center=nacos://10.32.52.57:8848?username=nacos&password=nacos
admin.metadata-report.address=nacos://10.32.52.57:8848?username=nacos&password=nacos
admin.registry.group=DEFAULT_GROUP
admin.config-center.group=DEFAULT_GROUP
admin.metadata-report.group=dubbo
admin.registry.namespace=public
admin.config-center.namespace=public
admin.metadata-report.namespace=public
admin.root.user.name=root
admin.root.user.password=root
admin.check.sessionTimeoutMilli=3600000
```

2. 通过配置提供者业务服务的“标签路由”，配置如下
```
enabled: true
force: true
runtime: false
tags:
- name: gray
addresses:
- '10.32.52.57:28861'
```

3. 服务消费者设置RPC上下文
`RpcContext.getClientAttachment().setAttachment("dubbo.tag", "gray");`

**问题：**
dubbo admin 的“服务查询”是存在相关业务服务的 rpc service . 看着整个 dubbo admin 的启动到配置都是正常且生效的。
**但是标签路由未生效， 没有命中配置的节点，还是会进行节点的负载调用**

Start by reproducing the label-routing configuration from application.properties with the Nacos registry and the consumer call using RpcContext.getClientAttachment().setAttachment("dubbo.tag", "gray"). Trace how the configured tag route is loaded and how the RPC attachment is used during provider selection. Done means calls with the gray tag select only the configured address and the behavior is covered by an appropriate test.

Written by the indexing model from the issue text.