fix: Fix subscription leak

[bigsheeper]

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issue: #36021

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[codecov]

Codecov Report

Attention: Patch coverage is 71.42857% with 4 lines in your changes missing coverage. Please review.

Project coverage is 83.26%. Comparing base (aed3b94) to head (02b2d66).
Report is 8 commits behind head on master.

Files with missing lines	Patch %	Lines
internal/rootcoord/dml_channels.go	71.42%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #37382      +/-   ##
==========================================
+ Coverage   81.03%   83.26%   +2.22%     
==========================================
  Files        1305     1015     -290     
  Lines      183190   157818   -25372     
==========================================
- Hits       148455   131412   -17043     
+ Misses      29533    21210    -8323     
+ Partials     5202     5196       -6     

Components	Coverage Δ
Client	∅ <ø> (∅)
Core	∅ <ø> (∅)
Go	83.29% <71.42%> (+0.02%)	⬆️

Files with missing lines	Coverage Δ
internal/rootcoord/dml_channels.go	96.62% <71.42%> (-1.47%)	⬇️

... and 320 files with indirect coverage changes

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/run-cpu-e2e

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/run-cpu-e2e

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rerun cpp-unit-test

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rerun go-sdk

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rerun cpp-unit-test

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@bigsheeper go-sdk check failed, comment rerun go-sdk can trigger the job again.

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