Node.js 16 actions are deprecated

[augustelalande]

Github actions are transitioning from node 16 to 20, planning to transition all actions to run on Node 20 by Spring 2024.

https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

Hopefully this shouldn't be much harder than just updating the node version in action.yml

[mathias-luedtke]

Thanks you very much for the reminder :)

Please test #847.

[augustelalande]

It ran without issue for me. Thanks.