Fix test failing on new node versions

[voxpelli]

There has been a subtle change in the error message for the Unexpected token JSON parsing error.

Easiest fix is this one here that changes the test to simply test for the inclusion of the phrase Unexpected token rather than the exact wording of the error.

Found when I tried to help debug #305

[kanongil]

Looks good. For more future-proofing, you might even do:

expect(err).to.be.an.error(SyntaxError, /JSON/);

[Marsup]

It seems to be a boom error though. I've made a suggestion and will try moving on if it passes. Tests seem to fail locally on options.baseUrl uses path when path is a full URL for me, no matter the version.

[Marsup]

Windows tests seem quite flaky, although node 20 might be legit, I'll merge it nonetheless.