feat: Add required_reviewers support to PullRequestRuleParameters (#3806)

[smazmi]

Summary

Adds support for GitHub's new ruleset feature that allows requiring specific team approvals on pull requests based on file patterns, as announced in the GitHub changelog on November 3, 2025.

Changes

This PR adds three new types to support the required_reviewers field in pull request ruleset parameters:

• RulesetReviewerType: Type-safe string enum for reviewer types
• RulesetRequiredReviewer: Contains minimum approvals, file patterns, and reviewer details
• RulesetReviewer: Nested struct with reviewer ID and type

The implementation follows existing patterns in the codebase (similar to BypassActorType) and uses pointer types for proper optionality and JSON omitempty semantics.

Testing

• Added comprehensive unit test case "pull_request_with_required_reviewers" that validates JSON marshaling/unmarshaling
• All existing tests pass
• Generated accessor methods with full test coverage

Additional Notes

The required_reviewers field is not yet documented in GitHub's OpenAPI schema but is confirmed working in production as of the November 3, 2025 announcement.

Resolves #3806

---

Checklist

• Added tests for new functionality
• Ran script/fmt.sh
• Ran script/generate.sh
• Ran script/test.sh
• Ran script/lint.sh
• Followed existing code patterns and conventions
• Added proper Go doc comments
• Verified against live GitHub API

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.27%. Comparing base (8760289) to head (6c2b2a4).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3811   +/-   ##
=======================================
  Coverage   92.27%   92.27%           
=======================================
  Files         192      192           
  Lines       13896    13896           
=======================================
  Hits        12823    12823           
  Misses        884      884           
  Partials      189      189           

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[gmlewis]

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

cc: @stevehipwell - @alexandear - @zyfy29

[smazmi]

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

cc: @stevehipwell - @alexandear - @zyfy29

Got it, thanks @gmlewis ! :)

[alexandear]

User is missing?

Suggested change

	RulesetReviewerTypeTeam RulesetReviewerType = "Team"
	)
	RulesetReviewerTypeTeam RulesetReviewerType = "Team"
	RulesetReviewerTypeUser RulesetReviewerType = "User"
	)

[smazmi]

Thanks for the review, @alexandear!

I originally added both Team and User reviewer types, but after testing, it looks like GitHub’s API only supports Team for the required_reviewers field.

What I found

• UI: Only teams can be selected.

• API tests:

  # Team
  curl -X POST .../rulesets -d '{"reviewer": {"type": "Team", "id": TEAM_ID}}'
  #  201 Created
  
  # User
  curl -X POST .../rulesets -d '{"reviewer": {"type": "User", "id": USER_ID}}'
  #  422 Unprocessable Entity (with error: `"data matches no possible input"`)

I tested this a few times, teams worked, users didn't.

I left User out of the enum since it’s not supported yet, but maybe I’m overlooking something.
Should I go ahead and add User back for future compatibility?