fix: [cherry-pick] Fix data race for clustering buffer writer

[xiaocai2333]

issue: #34495

master pr: #35145

[codecov]

Codecov Report

Attention: Patch coverage is 44.44444% with 5 lines in your changes missing coverage. Please review.

Project coverage is 81.08%. Comparing base (0bec383) to head (4178f1d).
Report is 8 commits behind head on 2.4.

Files	Patch %	Lines
...ternal/datanode/compaction/clustering_compactor.go	44.44%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              2.4   #35146      +/-   ##
==========================================
+ Coverage   81.07%   81.08%   +0.01%     
==========================================
  Files        1052     1052              
  Lines      136710   136710              
==========================================
+ Hits       110831   110849      +18     
+ Misses      21665    21652      -13     
+ Partials     4214     4209       -5     

Files	Coverage Δ
...ternal/datanode/compaction/clustering_compactor.go	65.91% <44.44%> (+0.26%)	⬆️

... and 30 files with indirect coverage changes

[czs007]

/approve
/lgtm

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: czs007, xiaocai2333

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• internal/datanode/OWNERS [czs007]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment