Add exempt as bypass mode to ruleset bypass actors

[claystation]

Fixes#3714

[gmlewis]

Thank you, @claystation!
One minor tweak, please, otherwise LGTM.

Note that I still don't have write access to this repo, but figure I might as well attempt to catch up on my code reviews (which I usually allow the linter to process first... ah, well).

[claystation]

@gmlewis no rush. Hope you get access back soon enough!

[gmlewis]

Thank you, @claystation!
LGTM.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.08%. Comparing base (f137c94) to head (484d81c).
⚠️ Report is 9 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3719 +/- ##
=======================================
Coverage 91.08% 91.08% =======================================
Files 187 187 Lines 16581 16581 =======================================
Hits 15103 15103 Misses 1293 1293 Partials 185 185 

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