test: Add tests for comment policy

[arkirchner]

Related to #2715

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.08%. Comparing base (393091c) to head (b91d16a).
Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3017      +/-   ##
==========================================
+ Coverage   70.05%   70.08%   +0.02%     
==========================================
  Files         215      215              
  Lines        6850     6850              
==========================================
+ Hits         4799     4801       +2     
+ Misses       2051     2049       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.