TestMicroserviceTSOClientSuite is flaky

## Flaky Test
### Which jobs are failing
```text
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2260397Z [2026/03/12 02:56:35.312 +00:00] [INFO] [raft] [zap_raft.go:77] ["ae7f38ba030a4413 [logterm: 1, index: 3] sent MsgPreVote request to 136dd459747cee69 at term 1"]
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2260832Z [2026/03/12 02:56:35.312 +00:00] [INFO] [raft] [zap_raft.go:77] ["ae7f38ba030a4413 [logterm: 1, index: 3] sent MsgPreVote request to 94204e2d2c71fd76 at term 1"]
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2260952Z coverage: 6.1% of statements in ../../...
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261060Z panic: test timed out after 5m0s
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261155Z running tests:
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261569Z TestMicroserviceTSOClientSuite (5m0s)
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261578Z
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261679Z goroutine 26786 [running]:
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2261778Z testing.(*M).startAlarm.func1()
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2262016Z /opt/hostedtoolcache/go/1.25.8/x64/src/testing/testing.go:2682 +0x605
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2262110Z created by time.goFunc
chunks (8, TSO Integration Test) UNKNOWN STEP 2026-03-12T02:56:39.2262308Z /opt/hostedtoolcache/go/1.25.8/x64/src/time/sleep.go:215 +0x45
```
### CI link
https://github.com/tikv/pd/actions/runs/22983139905/job/66730675006
https://prow.tidb.net/view/gs/prow-tidb-logs/pr-logs/pull/tikv_pd/10334/pull-unit-test-next-gen-3/2031971387177963520
### Reason for failure (if possible)

### Anything else
test=TestMicroserviceTSOClientSuite signatures=TIMEOUT_PANIC,PANIC,UNKNOWN_FAILURE