Fix testdouble.js for node > 20

[MartinKolarik]

There's node v24 already, but we still target v20 here because of an issue in one of the dev dependencies. I'd like to update both the API and our default probe builds to v24, which means we need to find a way to get our tests to work. There's a possible patch - if it works, this might be as easy as forking the main project and using that version until the fix is merged.

[alexey-yarmosh]

Looks like tests are passing with v24 - https://github.com/jsdelivr/globalping/compare/node24?expand=1
Am I missing something?

[MartinKolarik]

Hmm, I didn't actually try 24 as it was broken in 21 and 22, and the issue tracking it had no updates. I didn't expect an even higher version would work again - will check.

[alexey-yarmosh]

Btw locally on macOS it works both for v22 and v24.

[MartinKolarik]

Please try the probe repo - I can't reproduce it here anymore, but on the probe, I'm getting some failures both on 22 and 24, some of which seem related to this.