experimental-serverless-trace causes breaking build times and bundle sizes

[lindsaylevine]

This is an issue to combine some of the miscellaneous, lingering issues in next-on-netlify that are all:

1. solved by changing target: serverless to target: experimental-serverless-trace
2. negatively impacted by the increased build times / bundle sizes

The related, miscellaneous issues:
Preview mode broken in Next 10.0.2
Functions fail when using Firebase Admin SDK
Error enabling offline persistence with Firebase Web SDK and SSR

This also serves as a core issue/prerequisite before changing the default target we (a) recommend in the next-on-netlify docs (b) set in @netlify/plugin-nextjs.

An amazing PR has been merged to netlify/zip-it-and-ship-it to help address this issue, thanks to the hard work of @erezrokah and @ehmicky ❤️ . This will be released in the new year!

[erezrokah]

FYI, the PR will be released to our build system in the new year as @lindsaylevine said, but it is available now in the CLI.
Running netlify build or netlify deploy --build will use the improved bundling logic when using next-on-netlify.

[erezrokah]

A quick update on this issue.
The fix has been released to our build system and we're seeing improvements on both bundle sizes and build times.
If anyone has a specific issue with functions bundle sizes/bundling time please open a new issue, possibly with a reproduction repo.