feat(data_validator): line_cd が 2!lines.csv に存在するか検証する - #1676

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: TimonVS/pr-labeler-action@v5. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/