koordlet: optimize auditor UT with httptest.Server

[ZiMengSheng]

Ⅰ. Describe what this PR does

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how to verify it

Ⅳ. Special notes for reviews

V. Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in make test

[codecov]

Codecov Report

Merging #382 (3e1627d) into main (b54bb0c) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #382      +/-   ##
==========================================
- Coverage   66.57%   66.55%   -0.02%     
==========================================
  Files         116      116              
  Lines       11580    11580              
==========================================
- Hits         7709     7707       -2     
- Misses       3281     3283       +2     
  Partials      590      590              

Flag	Coverage Δ
unittests	66.55% <100.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/koordlet/audit/auditor.go	71.42% <100.00%> (ø)
pkg/koordlet/runtimehooks/reconciler/reconciler.go	78.94% <0.00%> (-2.11%)	⬇️

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[jasonliu747]

/lgtm

[eahydra]

/approve

[jasonliu747]

/lgtm

[hormes]

/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: eahydra, hormes, jasonliu747

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