fix: Org/Enterprise UpdateRepositoryRulesetClearBypassActor sends empty array

[dblinkhorn]

This PR Fixes the same bug in organization and enterprise rulesets that was fixed for repository rulesets in PR #3727 (issue #3726).

Changes

• Initialize BypassActors with empty slice instead of nil
• Add test validation to verify correct JSON payload is sent

Closes#3795.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.17%. Comparing base (53d0e6a) to head (0df563f).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3796 +/- ##
=======================================
Coverage 92.17% 92.17% =======================================
Files 191 191 Lines 13690 13692 +2 =======================================
+ Hits 12619 12621 +2 
Misses 883 883 Partials 188 188 

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[gmlewis]

Thank you, @dblinkhorn!
LGTM.
Awaiting second LGTM+Approval from any other contributor to this repo before merging.

cc: @stevehipwell - @alexandear - @zyfy29

[gmlewis]

Thank you, @alexandear!
Merging.