enhance: [2.5] clean up logs of empty op key

[shaoting-huang]

cherry-pick from master: #39335
related: #39334

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.01%. Comparing base (0c00f94) to head (426489c).
Report is 2 commits behind head on 2.5.

Files with missing lines	Patch %	Lines
internal/rootcoord/rbac_task.go	50.00%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              2.5   #39394      +/-   ##
==========================================
- Coverage   81.03%   81.01%   -0.02%     
==========================================
  Files        1404     1404              
  Lines      197572   197573       +1     
==========================================
- Hits       160100   160064      -36     
- Misses      31862    31891      +29     
- Partials     5610     5618       +8     

Components	Coverage Δ
Client	78.26% <ø> (ø)
Core	69.49% <ø> (ø)
Go	82.98% <50.00%> (-0.03%)	⬇️

Files with missing lines	Coverage Δ
internal/rootcoord/rbac_task.go	70.03% <50.00%> (+0.10%)	⬆️

... and 27 files with indirect coverage changes

[shaoting-huang]

rerun ut