This fixes the build failing due to attempting to read `edgeInfo` that
wasn't present from using the wrong key to look up the manifest entry.
Regression test added by enabling `experimental-edge` on a page that was
failing to be looked up.
Fixes:
```sh
TypeError: Cannot read properties of undefined (reading 'files')
at /Users/jj/dev/vercel/layouts-playground/node_modules/next/dist/build/utils.js:786:33
at Span.traceAsyncFn (/Users/jj/dev/vercel/layouts-playground/node_modules/next/dist/trace/trace.js:79:26)
at Object.isPageStatic (/Users/jj/dev/vercel/layouts-playground/node_modules/next/dist/build/utils.js:771:29)
```
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have a helpful link attached, see `contributing.md`
328c3a765a