feat: control concurrency when call CountWinner

[simlecode]

关联的Issues (Related Issues)

close filecoin-project/venus#6128

改动 (Proposed Changes)

附注 (Additional Info)

自查清单 (Checklist)

在你认为本 PR 满足被审阅的标准之前，需要确保 / Before you mark the PR ready for review, please make sure that:

• 符合Venus项目管理规范中关于PR的相关标准 / The PR follows the PR standards set out in the Venus project management guidelines
• 具有清晰明确的commit message / All commits have a clear commit message.
• 包含相关的的测试用例或者不需要新增测试用例 / This PR has tests for new functionality or change in behaviour or not need to add new tests.
• 包含相关的的指南以及文档或者不需要新增文档 / This PR has updated usage guidelines and documentation or not need
• 通过必要的检查项 / All checks are green

[codecov-commenter]

Codecov Report

Merging #223 (e43eac5) into release/v1.13 (b9e9167) will decrease coverage by 14.26%.
The diff coverage is 100.00%.

❗ Current head e43eac5 differs from pull request most recent head c4668d0. Consider uploading reports for the commit c4668d0 to get more accurate results

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@@                Coverage Diff                 @@
##           release/v1.13     #223       +/-   ##
==================================================
- Coverage          47.24%   32.98%   -14.26%     
==================================================
  Files                 45       61       +16     
  Lines               2464     4326     +1862     
==================================================
+ Hits                1164     1427      +263     
- Misses              1127     2725     +1598     
- Partials             173      174        +1     

Flag	Coverage Δ
unittests	32.84% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage
miner/miningmgr.go	100.00%
miner/util.go	100.00%

[LinZexiao]

LGTM