Update Emscripten binary wheels to include Emscripten platform tags. More work split off from #2591.

### Checklists

- [x] Add a [CHANGELOG](https://github.com/pyodide/pyodide/blob/main/docs/project/changelog.md) entry


# Credits

Based on the hard work of [@dgym](https://github.com/dgym) on
[cpython-emscripten](https://github.com/dgym/cpython-emscripten).

# Credits

Based on the hard work of [@dgym](https://github.com/dgym) on
[cpython-emscripten](https://github.com/dgym/cpython-emscripten).
