zig-based python-wasm status update after 3 weeks

[williamstein]

I've now made it so with our new Zig-based https://python-wasm.cocalc.com/:

• import time; time.sleep(10) actually works without being fake or burning 100% cpu
• control+c works pretty well
• readline is fully supported (via libedit, so BSD licensed).
• fully works both in nodejs and the browser

None of the above is true of the Pyodide demo at https://pyodide.org/en/stable/console.html

The next major challenge is building C extension modules and dynamically linking them, so we can build something like numpy. Moreover, we want to do this in a much better way than pyodide by not using native Python at all, but directly running python-wasm via node.js.