### What
Keep `test/e2e/app-dir/metadata-dynamic-routes/index.test.ts` with
successful build cases, move the dev error tests into separate test
### Why
x-ref:
https://github.com/vercel/next.js/actions/runs/9429301722/job/25975574075?pr=66286
Before the moving the tests, the error is flaky with turbopack since the
error will fail the hmr. Error observed with turbopack when seeing build
failed cases. So I moved the tests into the separate dev tests, running
inside sandboxes. Then each error test doesn't effect each other.
```
⨯ ./app/metadata-base/unset/icon--metadata.js:1:1
Module not found: Can't resolve './icon.tsx'
> 1 | import { generateImageMetadata } from "./icon.tsx"
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2 | import { fillMetadataSegment } from 'next/dist/lib/metadata/get-metadata-route'
3 |
4 | const imageModule = { generateImageMetadata }
```
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