test: fix flaky http timeout test

There is no guarantee that a timeout won't be delayed considerably due
to unrelated activity on the host. Instead of checking that the timeout
happens within a certain tolerance, simply check that it did not happen
too soon.

Fixes: https://github.com/nodejs/node/issues/22041

PR-URL: https://github.com/nodejs/node/pull/22403


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>