Ensure edge prerender-manifest is minimal (#64946)
This ensures we don't include the entire prerender-manifest in edge
runtime as it's un-necesary and can be very large. We only need the
preview field in this manifest so this ensures we just include that.
x-ref: [slack
thread](https://vercel.slack.com/archives/C0289CGVAR2/p1713904966662599?thread_ts=1713798297.067699&cid=C0289CGVAR2)
Closes NEXT-3212
