feat: update next plugin package to install

[ericapisani]

Currently blocked on other changes needing to be done first, have this open so it's ready to go when we need it

Summary

See this issue

A picture of a cute animal (not mandatory, but encouraged)

[ascorbic]

OK, can we change this so that it only applies for a feature flag? There should be examples somewhere.

[ericapisani]

@ascorbic I've added a check for a build_use_next_runtime feature flag, but just wanted to confirm that the systems for setting up a build would select the runtime first if the feature flag is enabled, or if there's additional filtering that needs to be done such as what we do for the minimum node version condition

[ascorbic]

Not using this now