feat(nextjs): Use `not: foreign` condition in turbopack loaders

[github-actions]

Note

The pull request "feat(nextjs): Use not: foreign condition in turbopack loaders" was created by @chargome but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

Just came across https://nextjs.org/docs/app/api-reference/config/next-config-js/turbopack#advanced-webpack-loader-conditions when researching for another issue.

We can match the turbopack loaders more strictly to only run on user code. Potentially reduces build times.

[linear]

JS-1798