We'll want a new test for the behavior this is guarding against.

while thinking on how to write a test for this one, logically the problem this pr solves it to get correct engine matched version, we only request for manifest from pacote with appropriate spec. earlier we were requesting npm@latest which gave us latest no matter what the node version is, but now we are fetching manifest with npm@* which gives us default tag ( latest ) if nothing matched otherwise highest appropriate version with engine consideration ( This logic is from npm-pick-manifest )
Do we need an end to end test here to show that it's marching based on engine ?

Do we need an end to end test here to show that it's matching based on engine ?

Yes, this is behavior we don't want to accidentally regress from. The update notifier tests will likely need a bit of tweaking to get there