Turbopack `require.context` ESM interop is different compared to Webpack

Originally reported by @Vinnl in https://github.com/vercel/next.js/pull/78148#issuecomment-2821067072 ### Link to the code that reproduces this issue https://github.com/Vinnl/tmp-repro-next-turbopack-require-context/commit/0878b97d96e1fdb8c7478531787073fb57e6f0b1 ### To Reproduce 1. Run `npm run dev` 2. Visit `http://localhost:3000/` 3. Observe the console (not the browser console), see `"File contents\n"` in the logs. 4. Terminate the process, then run `npm run dev-turbo` 5. Visit `http://localhost:3000/` ### Current vs. Expected behavior What happened: I saw `{"default":"File contents\n"}` in the logs. What I expected: See `"File contents\n"` in the logs, just like with the Webpack build. ### Provide environment information ```bash Operating System: Platform: linux Arch: x64 Version: #1 SMP PREEMPT_DYNAMIC Thu Apr 10 21:50:55 UTC 2025 Available memory (MB): 15691 Available CPU cores: 8 Binaries: Node: 20.11.0 npm: 10.2.4 Yarn: 1.22.19 pnpm: 9.4.0 Relevant Packages: next: 15.4.0-canary.2 // Latest available version is detected (15.4.0-canary.2). eslint-config-next: N/A react: 19.1.0 react-dom: 19.1.0 typescript: 5.8.3 Next.js Config: output: N/A ``` ### Which area(s) are affected? (Select all that apply) Turbopack ### Which stage(s) are affected? (Select all that apply) next dev (local) ### Additional context _No response_