Upgrade from Node.js 20 to Node.js 24

[stefanahman]

GitHub Actions running on Node.js 20 are deprecated. Actions will be forced to run with Node.js 24 by default starting June 2, 2026.

The action currently declares using: node20 in action.yml. This produces the following warning on every workflow run:

Warning: Node.js 20 actions are deprecated. Please check if updated versions of these actions are available that support Node.js 24.

Please update to node24 to suppress the deprecation warning and ensure continued compatibility.

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

[rjonsson]

This PR was recently closed that addresses it:
#294

[jakehockey10]

Also, there was already an issue about this #286 .

[stefanahman]

Oh sorry, missed that. I was looking at the latest version and still node 20, perhaps stale/cached view. Thanks a lot!