goleak in the TestImportInto with real tikv

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

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

### 3. What did you see instead (Required)

```
PASS

goleak: Errors on successful test run: found unexpected goroutines:

[Goroutine 216376 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01cbc7530?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xc01d9bbe80?, 0xc00478efd0?}}, 0xc00478efa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9810)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216382 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc019df6b40?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x3433a?, 0xc00407dfd0?}}, 0xc00407dfa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9c30)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216383 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc013b4ff20?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x24f?, 0xc009434fd0?}}, 0xc009434fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9ce0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216385 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc013b4fef0?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xb76db48?, 0xc002d7cfd0?}}, 0xc002d7cfa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9e40)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216377 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc013b4fec0?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x3444d?, 0xc004035fd0?}}, 0xc004035fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb98c0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216386 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01baebe00?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xb76db48?, 0xc005aeefd0?}}, 0xc005aeefa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00efa4000)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216378 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01baebe30?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x3444d?, 0xc003d61fd0?}}, 0xc003d61fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9970)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216387 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01cbc75c0?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x8d8fec5?, 0xc003006fd0?}}, 0xc003006fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00efa40b0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216389 in state sync.Cond.Wait, 2 minutes, with sync.runtime_notifyListWait on top of the stack:

sync.runtime_notifyListWait(0xc009b500a0, 0x0)

GOROOT/src/runtime/sema.go:606 +0x159

sync.(*Cond).Wait(0xc009b50090)

GOROOT/src/sync/cond.go:71 +0x6c

github.com/cockroachdb/pebble/record.(*flusherCond).Wait(...)

external/com_github_cockroachdb_pebble/record/log_writer.go:204

github.com/cockroachdb/pebble/record.(*LogWriter).flushLoop(0xc009b50000, {0xc01870f440?, 0x9da51c0?})

external/com_github_cockroachdb_pebble/record/log_writer.go:436 +0xbb4

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84ae0?, 0x97fc830?, 0x7f343f1cc300?}}, 0xc00612dfc0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble/record.NewLogWriter.func2()

external/com_github_cockroachdb_pebble/record/log_writer.go:355 +0x92

created by github.com/cockroachdb/pebble/record.NewLogWriter in goroutine 214343

external/com_github_cockroachdb_pebble/record/log_writer.go:354 +0x65f

Goroutine 216380 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc019df6b70?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xc01f34eb08?, 0xc00966bfd0?}}, 0xc00966bfa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9ad0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216373 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc019df6b10?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xb76db48?, 0xc0029b2fd0?}}, 0xc0029b2fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9550)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216384 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01a491f50?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x34030?, 0xc0053e8fd0?}}, 0xc0053e8fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9d90)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216374 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc013b4fe90?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xc015479d00?, 0xc009544fd0?}}, 0xc009544fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb96b0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216375 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01cbc7560?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xc01d9bbe80?, 0xc008946fd0?}}, 0xc008946fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9760)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216388 in state select, with github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker.func1 on top of the stack:

github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker.func1()

external/com_github_cockroachdb_pebble/vfs/disk_health.go:171 +0x18f

created by github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker in goroutine 214343

external/com_github_cockroachdb_pebble/vfs/disk_health.go:166 +0xa8

Goroutine 216257 in state select, with github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker.func1 on top of the stack:

github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker.func1()

external/com_github_cockroachdb_pebble/vfs/disk_health.go:171 +0x18f

created by github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFile).startTicker in goroutine 214343

external/com_github_cockroachdb_pebble/vfs/disk_health.go:166 +0xa8

Goroutine 216379 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01cbc7590?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x25a12f1?, 0xc0055e9fd0?}}, 0xc0055e9fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9a20)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216381 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc019df6ba0?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0x3444d?, 0xc00a147fd0?}}, 0xc00a147fa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb9b80)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216372 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1 on top of the stack:

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop.func1({0xb6b5838?, 0xc01cbc7500?})

external/com_github_cockroachdb_pebble/table_cache.go:385 +0xda

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84dc0?, 0xc000c92dc8?, 0xc0053edfd0?}}, 0xc0053edfa0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.(*tableCacheShard).releaseLoop(0xc00cfb89a0)

external/com_github_cockroachdb_pebble/table_cache.go:383 +0x92

created by github.com/cockroachdb/pebble.(*tableCacheShard).init in goroutine 214343

external/com_github_cockroachdb_pebble/table_cache.go:375 +0x17f

Goroutine 216256 in state select, with github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFS).startTickerLocked.func1 on top of the stack:

github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFS).startTickerLocked.func1()

external/com_github_cockroachdb_pebble/vfs/disk_health.go:566 +0x193

created by github.com/cockroachdb/pebble/vfs.(*diskHealthCheckingFS).startTickerLocked in goroutine 214343

external/com_github_cockroachdb_pebble/vfs/disk_health.go:555 +0xfd

Goroutine 216371 in state chan receive, 2 minutes, with github.com/cockroachdb/pebble.(*cleanupManager).mainLoop on top of the stack:

github.com/cockroachdb/pebble.(*cleanupManager).mainLoop(0xc00c240000)

external/com_github_cockroachdb_pebble/cleaner.go:155 +0x29d

github.com/cockroachdb/pebble.openCleanupManager.func1.1({0xb6b5838?, 0xc013b4fe60?})

external/com_github_cockroachdb_pebble/cleaner.go:86 +0x2f

runtime/pprof.Do({0xb6b56d8, 0x10dfed40}, {{0xc000a84d80?, 0x97fc830?, 0x7f343f1a1a00?}}, 0xc0040b9fc0)

GOROOT/src/runtime/pprof/runtime.go:51 +0x112

github.com/cockroachdb/pebble.openCleanupManager.func1()

external/com_github_cockroachdb_pebble/cleaner.go:85 +0x92

created by github.com/cockroachdb/pebble.openCleanupManager in goroutine 214343

external/com_github_cockroachdb_pebble/cleaner.go:84 +0x4eb

]

```
### 4. What is your TiDB version? (Required)