Skips additional production-only tests.
Follow-up to #56089.
In this PR I went through all of `test/integration` looking for `nextBuild(` and added the skipping logic.
The `target: serverless` config was deprecated a year ago starting in
[Next.js 12](https://nextjs.org/blog/next-12).
Tests were disabled in #41252 so we can now remove `target: serverless`
and all usage of `target` in `next.config.js`.
Co-authored-by: Balázs Orbán <info@balazsorban.com>
Co-authored-by: JJ Kasper <jj@jjsweb.site>