br: should skip the error "object doesn't exist" when delete file(delete object).

## Enhancement
```
9 error: cluster tidb1379661944635664065/log-ab-1379661944635664065-11, wait pipe message failed, errMsg [2023/03/20 04:43:49.406 +00:00] [ERROR] [stream.go:456] ["failed to stream"] [command="log truncate"] [error="failed to write back file v1/backupmeta/440028758403186689-30626999-a242-4a87-94ff-cb5f8175bbf8.meta: failed to remove the empty meta v1/backupmeta/440028758403186689-30626999-a242-4a87-94ff-cb5f8175bbf8.meta: storage: object doesn't exist"] [errorVerbose="storage: object doesn't exist
github.com/pingcap/errors.AddStack
/go/pkg/mod/github.com/pingcap/errors@v0.11.5-0.20211224045212-9687c2b0f87c/errors.go:174
github.com/pingcap/errors.Trace
/go/pkg/mod/github.com/pingcap/errors@v0.11.5-0.20211224045212-9687c2b0f87c/juju_adaptor.go:15
github.com/pingcap/tidb/br/pkg/storage.(*gcsStorage).DeleteFile
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/storage/gcs.go:102
github.com/pingcap/tidb/br/pkg/restore.(*StreamMetadataSet).doWriteBackForFile
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/restore/stream_metas.go:266
github.com/pingcap/tidb/br/pkg/restore.(*StreamMetadataSet).removeDataFilesAndUpdateMetadata
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/restore/stream_metas.go:254
github.com/pingcap/tidb/br/pkg/restore.(*StreamMetadataSet).RemoveDataFilesAndUpdateMetadataInBatch.func1
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/restore/stream_metas.go:184
github.com/pingcap/tidb/br/pkg/utils.(*WorkerPool).ApplyOnErrorGroup.func1
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/utils/worker.go:76
golang.org/x/sync/errgroup.(*Group).Go.func1
/go/pkg/mod/golang.org/x/sync@v0.0.0-20220722155255-886fb9371eb4/errgroup/errgroup.go:75
runtime.goexit
/usr/local/go/src/runtime/asm_amd64.s:1594
failed to remove the empty meta v1/backupmeta/440028758403186689-30626999-a242-4a87-94ff-cb5f8175bbf8.meta
failed to write back file v1/backupmeta/440028758403186689-30626999-a242-4a87-94ff-cb5f8175bbf8.meta"] [stack="github.com/pingcap/tidb/br/pkg/task.RunStreamCommand
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/pkg/task/stream.go:456
main.streamCommand
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/cmd/br/stream.go:231
main.newStreamTruncateCommand.func1
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/cmd/br/stream.go:143
github.com/spf13/cobra.(*Command).execute
/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:872
github.com/spf13/cobra.(*Command).ExecuteC
/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:990
github.com/spf13/cobra.(*Command).Execute
/go/pkg/mod/github.com/spf13/cobra@v1.5.0/command.go:918
main.main
/home/jenkins/agent/workspace/build-common/go/src/github.com/pingcap/br/br/cmd/br/main.go:57
runtime.main
/usr/local/go/src/runtime/proc.go:250"]
```