Can not define multiple explicit clients with multiple services

RLC case:
https://github.com/Azure/autorest.typescript/blob/main/packages/typespec-ts/test/unit/clientUtil.spec.ts#L78
https://github.com/Azure/autorest.typescript/blob/main/packages/typespec-ts/test/unit/clientUtil.spec.ts#L112

typespec:
```
import "@azure-tools/typespec-client-generator-core";
using Azure.ClientGenerator.Core;

@service
namespace MyService {
@client({
name: "MyClient",
service: MyService
})
interface MyInterface {
op1(): void
}
}

@service
namespace MySecondService {
@client({
name: "MySecondClient",
service: MySecondService
})
interface MySecondInterface {
op1(): void
}
}
```

error log: