tests: Replace use of preq with node-fetch

[jdforrester]

Bug: T293853
Bug: T309772

[santhoshtr]

If we increase the node version to 18(LTS, Maintainance mode) or later, 'fetch' API is standardized and stable in node. No need for an external library.
(cxserver just migrated away from preq using node native fetch https://phabricator.wikimedia.org/T350773)

[jdforrester]

If we increase the node version to 18(LTS, Maintainance mode) or later, 'fetch' API is standardized and stable in node. No need for an external library. (cxserver just migrated away from preq using node native fetch https://phabricator.wikimedia.org/T350773)

Yes, but other parts of the library aren't yet compatible with Node 18, so we can't do that right now (until I or someone else has the time to fix those incompatibilities).

[mvolz]

Not sure what's causing the errors here, but as I'm looking into preq for an unrelated issue, I thought I should note it differs from fetch in at least two ways:

Preq is wrapping errors, so we might loose some logging features upstream if those are not replaced upstream;

Preq uses another defunct library called requestretry to automatically retry requests once after a short time out.

[jdforrester]

Not sure what's causing the errors here, but as I'm looking into preq for an unrelated issue, I thought I should note it differs from fetch in at least two ways:

Preq is wrapping errors, so we might loose some logging features upstream if those are not replaced upstream;

Preq uses another defunct library called requestretry to automatically retry requests once after a short time out.

Yeah, those two are things to bear in mind for downstream users if they're just preq in prod code, but given this is tests-only here I think it should be fine. But then, it's breaking tests (or something else is), so… :-(