DOCS: Update docs to reflect version 3.12

## 📚 Documentation Update docs to reflect version 3.12

There's quite a few areas in the documentation that [still point to version 3.11](https://github.com/search?q=repo%3Apyodide%2Fpyodide+path%3A%2F%5Edocs%5C%2F%2F+3.11&type=code), even though [3.12 is supported](https://github.com/pyodide/pyodide/pull/4435).

This would be fine, but I wasn't able to build with this version due to the [update requiring 3.12 in this commit](https://github.com/pyodide/pyodide/commit/7dd2c64639f14afb86c01ebbb6dc0143f6cf6183).
I don't know enough to just wing it and revert to the 3.11 requirement.

I'm on a Mac M1 building locally so this may be why it is griping at me as its likely a very picky build process on this arch.

Happy to contribute docs if this is the right way to go.

FYI, this also breaks using `3.12.2` I believe due to the cython deps, so I will try with `3.12.1` and report back if I get this working.