As mentioned in #97

noticed that time.sleep() is a no op in the pyodide's cpython webassembly runtime. As cpython implements it using select.select()'s timeout, it's not really a surprise that it's not supported by pyodide.

It would be good to provide a different implementation for time.sleep since sync code cannot use await asyncio.sleep

For instance, emscripten's musl has __clock_nanosleep but this might need threading enabled.

Other possible solutions were discussed in #97