[Bug] removing the so-called registry config duplication leads to exception

### Pre-check

- [x] I am sure that all the content I provide is in English.

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/dubbo/issues?q=is%3Aissue) and found no similar issues.

### Apache Dubbo Component

Java SDK (apache/dubbo)

### Dubbo Version

Dubbo 3.3.6，openjdk 21

### Steps to reproduce this issue

if the dubbo consumer xml config is as follow

```

```

in which ZK1_ADDRESS and ZK2_ADDRESS are env variables.

what is exactly needed is that ZK1_ADDRESS and ZK2_ADDRESS may be the same or different.

when ZK1_ADDRESS and ZK2_ADDRESS are the same, current implementation will only register zk1 registy config successfully, the zk2 registry config is identified as duplication，then it throws exception `java.lang.IllegalStateException: Registry not found: zk2` when loading app2 reference config

### What you expected to happen

zk1 and zk2 are all registered successfully.

### Anything else

_No response_

### Do you have a (mini) reproduction demo?

- [ ] Yes, I have a minimal reproduction demo to help resolve this issue more effectively!

### Are you willing to submit a pull request to fix on your own?

- [x] Yes I am willing to submit a pull request on my own!

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

Start with the consumer XML registry and reference-loading paths described in the report, then trace how registry configurations are deduplicated when their resolved addresses match. Reproduce the zk1/zk2 case with identical and different environment-variable values; done when both named registries remain available and app2 loads without the Registry not found exception.

Written by the indexing model from the issue text.