This ensures `distDir` is set under `renderOpts` in `next-server` so that it is present when experimental `optimizeCss` is enabled. x-ref: https://github.com/vercel/next.js/pull/16539
Adding test for experimental-serverless-trace + fix for the same
Co-authored-by: JJ Kasper <jj@jjsweb.site> Co-authored-by: Joe Haddad <joe.haddad@zeit.co>