매주 일요일 주차 마무리를 자동 실행하는 워크플로우 추가 - #2809

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: toshimaru/auto-author-assign@v2.1.0. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/