ci: bump node version

[afuetterer]

Should we switch to the active LTS v24 (Krypton)?
https://nodejs.org/en/about/previous-releases

[jochenklar]

Hi @afuetterer , yes we should do this for RDMO 2.5.0 (and then we need to check that everything works). Give me a two weeks, I need to work on 2.5.0/release and rebase it first.

[afuetterer]

• .nvmrc
• package.json
• .github/workflows/ci.yml

Ref: https://github.com/search?q=repo%3Ardmorganiser%2Frdmo+22.22&type=code