fix preserve Dependabot reviewer intent

[Pigbibi]

What changed

• model both review_requested and review_request_removed timeline events
• paginate the complete PR timeline
• re-check current reviewer state immediately before deletion
• preserve the latest human request/removal intent during concurrent updates
• restore a human request only when it is still the latest human action and currently absent
• handle concurrent DELETE races without hiding genuine API failures

Why

This closes the remaining reviewer-state races in Dependabot CODEOWNERS cleanup. A maintainer can request or withdraw review while cleanup is queued without having that intent overwritten.

Validation

• bash syntax check
• jq event-state fixture check
• git diff --check
• no checkout or execution of PR code

[github-actions]

🤖 Codex PR Review

✅ Merge allowed: No issues found

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Review by Codex PR Review bot • PR