contrib: remaining errors.Is conversions

[redwrasse]

Remaining errors.Is conversions for contrib directory, as part of #18576.

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[k8s-ci-robot]

Hi @redwrasse. Thanks for your PR.

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[codecov-commenter]

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.79%. Comparing base (6ea81c1) to head (75879c1).

❗ Current head 75879c1 differs from pull request most recent head f6278ef

Please upload reports for the commit f6278ef to get more accurate results.

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Additional details and impacted files

see 15 files with indirect coverage changes

@@            Coverage Diff             @@
##             main   #18616      +/-   ##
==========================================
+ Coverage   68.78%   68.79%   +0.01%     
==========================================
  Files         420      420              
  Lines       35519    35519              
==========================================
+ Hits        24431    24435       +4     
+ Misses       9662     9658       -4     
  Partials     1426     1426              

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