Update release workflow actions for Node 24 compatibility

[swashbuck]

Subject of the enhancement

The reusable release.yml workflow uses actions/checkout@v4 and actions/setup-node@v4, which run on Node.js 20. GitHub will force these to Node.js 24 on 2026-06-16 and remove Node 20 from runners on 2026-09-16, so they emit deprecation warnings now and will fail later.

https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

• actions/checkout@v4 → using: node20 — https://github.com/actions/checkout/blob/v4/action.yml
• actions/setup-node@v4 → using: node20 — https://github.com/actions/setup-node/blob/v4/action.yml

Plan

• Bump actions/checkout and actions/setup-node to v6 (Node 24) in release.yml.
• This is a reusable workflow, so every consuming repo inherits the bump on its next release run.

Notes

Mirrors the same fix in cgkineo/.github (cgkineo/cgkineo#11 / cgkineo/.github#3). The node-version input is unchanged; only the action runtime moves to Node 24.

Posted via collaboration with Claude Code