fix: gc only do once

[chyezh]

issue: #29655

produced by pr: #31740

[czs007]

/approve
/lgtm

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.73%. Comparing base (6289f3a) to head (aa9e55f).
Report is 6 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #32722   +/-   ##
=======================================
  Coverage   81.72%   81.73%           
=======================================
  Files         998      998           
  Lines      124209   124292   +83     
=======================================
+ Hits       101513   101589   +76     
+ Misses      18822    18820    -2     
- Partials     3874     3883    +9     

Files	Coverage Δ
internal/datacoord/garbage_collector.go	88.80% <100.00%> (ø)

... and 37 files with indirect coverage changes