POTENTIAL DEADLOCK in test

## Flaky Test

### Which jobs are failing

```
POTENTIAL DEADLOCK:
Previous place where the lock was grabbed
goroutine 1153 lock 0xc004e4d410
../cluster.go:144 tests.(*TestServer).Run { s.Lock() } <<<<<
../cluster.go:143 tests.(*TestServer).Run { func (s *TestServer) Run() error { }
../cluster.go:651 tests.RunServer.func1 { resC := make(chan error) }

Have been trying to lock it again for more than 30s
goroutine 281 lock 0xc004e4d410
../cluster.go:221 tests.(*TestServer).State { s.RLock() } <<<<<
../cluster.go:220 tests.(*TestServer).State { func (s *TestServer) State() int32 { }
../cluster.go:701 tests.(*TestCluster).runInitialServersWithRetry { for _, s := range servers { }
server_test.go:86 server_test.TestUpdateAdvertiseUrls { err = cluster.RunInitialServers() }
../cluster.go:670 tests.(*TestCluster).RunInitialServers { // RunInitialServers starts to run servers in InitialServers. }

Here is what goroutine 1153 doing now
goroutine 1153 [select]:
github.com/tikv/pd/server.(*Server).startEtcd(0xc004718f08, {0x7272848, 0xc00054dae0})
/home/runner/work/pd/pd/server/server.go:356 +0x38f
github.com/tikv/pd/server.(*Server).Run(0xc004718f08)
/home/runner/work/pd/pd/server/server.go:627 +0x1af
github.com/tikv/pd/tests.(*TestServer).Run(0xc004e4d410)
/home/runner/work/pd/pd/tests/cluster.go:149 +0x1c7
github.com/tikv/pd/tests.RunServer.func1()
/home/runner/work/pd/pd/tests/cluster.go:652 +0x45
created by github.com/tikv/pd/tests.RunServer in goroutine 281
/home/runner/work/pd/pd/tests/cluster.go:652 +0x13a

```

### CI link

https://github.com/tikv/pd/actions/runs/21736731318/job/62703210572

### Reason for failure (if possible)

### Anything else