Update Sanity example deps and tsconfig (#64570)
v3.38.0 of `sanity` fixes a couple of bugs affecting Next.js:
- [crash in hotspot and cropping on
Next.js](https://github.com/sanity-io/sanity/pull/6380)
- [regression hiding tool buttons when embedded on
Next.js](https://github.com/sanity-io/sanity/pull/6338)
Also adjusts the `tsconfig.json` to use `module: Preserve`.
