fix: lazy load sharp (#65484)
> [!NOTE]
> This PR is easiest to review without whitespace.
> See https://github.com/vercel/next.js/pull/65484/files?w=1
This PR fixes an issue where importing `image-optimization` was loading
sharp but we don't want to load it until we attempt to optimize an
image. So this PR changes it to lazy load on first invocation to avoid
metadata trying to initialize sharp.
Closes NEXT-3355
