optimizePackageImports' caches index.ts files (dev and build) when they resolve to source files outside node_modules.

### Link to the code that reproduces this issue https://github.com/threehams/next-optimize-caching ### To Reproduce Dev caching: 1. Run `npm run dev` 2. Add a syntax error to `ui/index.ts` Build caching: 1. Run `npm run build` 2. Rename `ui/Button.tsx` to `ui/CounterButton.tsx`, and update imports in `ui/index.ts` 3. Run `npm run build` again ### Current vs. Expected behavior Current: Dev caching: The syntax error is not reported. The dev server caches the contents of `index.ts` file until server restart. Build caching: ``` ./ui/index.ts Module not found: Can't resolve './Button' ``` The build caches the `index.ts` file permanently, and will fail until the `.next` directory is deleted. Expected: The [Next.js 14.2 release notes](https://nextjs.org/blog/next-14-2#tree-shaking) encourage using `optimizePackageImports: ['package-name']` to optimize barrel files. When these files are outside `node_modules`, the imports should be re-evaluated when those `index.ts` files have changed on disk, in both dev and production builds. ### Provide environment information ```bash Operating System: Platform: darwin Arch: arm64 Version: Darwin Kernel Version 23.4.0: Fri Mar 15 00:10:42 PDT 2024; root:xnu-10063.101.17~1/RELEASE_ARM64_T6000 Available memory (MB): 32768 Available CPU cores: 10 Binaries: Node: 20.10.0 npm: 10.2.5 Yarn: 1.22.19 pnpm: 9.1.0 Relevant Packages: next: 14.2.3 // Latest available version is detected (14.2.3). eslint-config-next: 14.2.3 react: 18.3.1 react-dom: 18.3.1 typescript: 5.4.5 Next.js Config: output: N/A ``` ### Which area(s) are affected? (Select all that apply) Developer Experience, SWC ### Which stage(s) are affected? (Select all that apply) next dev (local), next build (local) ### Additional context _No response_