Backfill the current turbopack version to nextjs 14

[PrivFelixKniest]

Goals

1. Make the current turbopack version available for the latest nextjs 14 release

Non-Goals

1. Make turbopack stable for builds etc. in nextjs 14

Background

Migrating a medium to large application from nextjs 14 to 15 is essentially impossible for me. The changes from 14 to 15 are bad enough, I would have to manually edit houndreds of api endpoints to add an await to the params etc. because of the way that the codemod works or rather doesnt work with my architecture, but third party support makes it even worse...

Finally it seems like all libraries support react 19 or next 15 and now Im stuck reading through forums on how upgrading auth0-nextjs from 3 to 4 was the worst documented most broken upgrade they have ever done with the whole api basically changing... not exactly confidence inspiring 3 hours deep into the upgrade.

Ive tried upgrading three times now - getting stuck somewhere along the road. And the only reason I want to upgrade is because its such a pain in the ass to keep developing my application on webpack because it is soooooo sloooooowww and turbopack in next 14 is not only broken, but also doesnt give any helpful error messages.

Proposal

If possible, please backfill some form of a recent turbopack version into a next 14 release I can upgrade to. It doesnt need to say "stable", it shouldnt be for builds and you dont need to maintain it longterm. Just something I can use right now to write my app more efficiently without upgrading.

What do you think?