update labels API not work for some modules

[you06]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. start a tidb server
2. check there are no labels

curl 127.0.0.1:10080/info/all
{
 "servers_num": 1,
 "owner_id": "d807298d-d747-4ded-b896-480beceed704",
 "is_all_server_version_consistent": true,
 "all_servers_info": {
  "d807298d-d747-4ded-b896-480beceed704": {
   "version": "8.0.11-TiDB-v8.0.0-alpha-208-gf0a26dd2a3",
   "git_hash": "f0a26dd2a36d688d9a691302edb5429d1f15e351",
   "ddl_id": "d807298d-d747-4ded-b896-480beceed704",
   "ip": "127.0.0.1",
   "listening_port": 4000,
   "status_port": 10080,
   "lease": "45s",
   "binlog_status": "Off",
   "start_timestamp": 1709205226,
   "labels": {},
   "server_id": 914
  }
 }
}

3. update labels

curl -X POST -d "{\"foo\": \"bar\"}" 127.0.0.1:10080/labels
{
 "foo": "bar"
}%

Also check the log

[2024/02/29 20:16:50.815 +09:00] [INFO] [tikv_handler.go:2005] ["update server labels"] [labels="{\"foo\":\"bar\"}"]

4. check the labels again by curl 127.0.0.1:10080/info/all

2. What did you expect to see? (Required)

curl 127.0.0.1:10080/info/all
{
 "servers_num": 1,
 "owner_id": "d807298d-d747-4ded-b896-480beceed704",
 "is_all_server_version_consistent": true,
 "all_servers_info": {
  "d807298d-d747-4ded-b896-480beceed704": {
   "version": "8.0.11-TiDB-v8.0.0-alpha-208-gf0a26dd2a3",
   "git_hash": "f0a26dd2a36d688d9a691302edb5429d1f15e351",
   "ddl_id": "d807298d-d747-4ded-b896-480beceed704",
   "ip": "127.0.0.1",
   "listening_port": 4000,
   "status_port": 10080,
   "lease": "45s",
   "binlog_status": "Off",
   "start_timestamp": 1709205226,
   "labels": {"foo": "bar"}, // there should be labels
   "server_id": 914
  }
 }
}

3. What did you see instead (Required)

curl 127.0.0.1:10080/info/all
{
 "servers_num": 1,
 "owner_id": "d807298d-d747-4ded-b896-480beceed704",
 "is_all_server_version_consistent": true,
 "all_servers_info": {
  "d807298d-d747-4ded-b896-480beceed704": {
   "version": "8.0.11-TiDB-v8.0.0-alpha-208-gf0a26dd2a3",
   "git_hash": "f0a26dd2a36d688d9a691302edb5429d1f15e351",
   "ddl_id": "d807298d-d747-4ded-b896-480beceed704",
   "ip": "127.0.0.1",
   "listening_port": 4000,
   "status_port": 10080,
   "lease": "45s",
   "binlog_status": "Off",
   "start_timestamp": 1709205226,
   "labels": {}, // there are no labels instead
   "server_id": 914
  }
 }
}

4. What is your TiDB version? (Required)

Release Version: v8.0.0-alpha-208-gf0a26dd2a3
Edition: Community
Git Commit Hash: f0a26dd2a36d688d9a691302edb5429d1f15e351
Git Branch: HEAD
UTC Build Time: 2024-02-06 03:48:06
GoVersion: go1.21.6
Race Enabled: false
Check Table Before Drop: false
Store: tikv