Next.js will not compile when there is a python notebook `.pynb` file present

[zshanhui]

1. Start a new next.js saas starter app.
2. Add a folder and create python notebook file
3. run npm run dev, and observe that the compilation is stuck (silently) without any errors or warnings

Expected behavior: Next.js compiles without any issues since python notebooks are normal files like .py or .txt and should not effect Next.js compilation.