testutils: add ExpectExactNTimes function to LogObserver

[clement2026]

Context https://github.com/etcd-io/etcd/pull/18635#discussion_r1775086281

#18635 needs this.

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[codecov-commenter]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 68.81%. Comparing base (5704c61) to head (136409c). :warning: Report is 1668 commits behind head on main.

:warning: Current head 136409c differs from pull request most recent head 5b38a8f

Please upload reports for the commit 5b38a8f to get more accurate results.

Additional details and impacted files

see 23 files with indirect coverage changes

@@            Coverage Diff             @@
##             main   #18637      +/-   ##
==========================================
+ Coverage   68.77%   68.81%   +0.03%     
==========================================
  Files         420      420              
  Lines       35535    35535              
==========================================
+ Hits        24439    24452      +13     
+ Misses       9666     9651      -15     
- Partials     1430     1432       +2     

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[serathius]

Do we really need to check if compacted Raft log occured at most N times? This is hard to check, why checking if "compact-index": X is not enough ?

[k8s-ci-robot]

PR needs rebase.

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.