fix(next): Ensure inline Sourcemaps are generated for wrapped modules in Dev

[github-actions]

Note

The pull request "fix(next): Ensure inline Sourcemaps are generated for wrapped modules in Dev" was created by @logaretm but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

This fixes breakpoints for editors like VSCode/Cursor in server-side code.

I have verified that breakpoints work in:

• Server-side app router components
• Server-side pages router functions and static params
• API endpoints and server-side functions
• middleware

This only affects webpack, and doesn't change anything for prod builds.

[linear]

JS-1374