I think (but can't now find a reference to it) that you're supposed to tell INZ any changes while you're on a temporary work visa. You could check by phoning in a general query without giving your name. I guess you're itching not to be at work for a while, and there are chances that they wouldn't find out, but what you would be
risking if you resign without a job to go to would be your right to remain. Your choice.
You can be granted a visa for a job that has a 90-day trial period, because there is a provision for what happens if the employer dismisses you during that time. See Option B here.
https://www.immigration.govt.nz/new-...at-will-happen