fix: etcd txn exceeds limit due to too many fields

[longjiquan]

fix: #33038

[xiaofan-luan]

/lgtm
/approve

[smellthemoon]

/lgtm

[mergify]

@longjiquan E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[codecov]

Codecov Report

Attention: Patch coverage is 71.42857% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 82.09%. Comparing base (a984e46) to head (eef7537).
Report is 10 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #33040      +/-   ##
==========================================
+ Coverage   82.04%   82.09%   +0.04%     
==========================================
  Files        1005     1005              
  Lines      127642   127653      +11     
==========================================
+ Hits       104729   104797      +68     
+ Misses      18932    18886      -46     
+ Partials     3981     3970      -11     

Files	Coverage Δ
internal/metastore/kv/rootcoord/kv_catalog.go	89.40% <100.00%> (+0.04%)	⬆️
internal/metastore/kv/rootcoord/suffix_snapshot.go	82.31% <50.00%> (-0.51%)	⬇️

... and 32 files with indirect coverage changes

[czs007]

/approve
/lgtm

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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