Update GitHub actions, fix NPMv16 deprecation

[thePanz]

Update to use latest v4.x for:

• actions/checkout → solves NPMv16 deprecation
• actions/cache

Use latest Ubuntu, upgrade from ubuntu-20.04

[tobias-93]

If you can get the JS test running again I will merge this.

[thePanz]

Hi @tobias-93 I tried but my got stuck :disappointed:

I would need some help here, not sure why that test if failing, looks like the tool is not available or installed :shrug:

[tobias-93]

Looks like both PhantomJS and the Google Closure Library which are being used for the JS unit tests are legacy tools which are no longer supported. This means that the JS tests need to be rewritten to a new library, for which Google (the developers, not the search engine) suggests Jasmine, Chai, Mocha, Jest, etc. This has no high priority for me, but feel free to see if you can rework the tests if you are familiar with any of these frameworks or if you feel like learning one of these.

[tobias-93]

This has been superseded with #500, thanks anyway!

[thePanz]

Nice, thank you for following up on this! :+1: