pyscript: PyodideRuntime.run should not `await`

I noticed this while looking at the source code.

Runtime.run is marked async: https://github.com/pyscript/pyscript/blob/aa85f5f5964e61f47b77cac73511d3d74c63328d/pyscriptjs/src/runtime.ts#L52-L57

But then when we call pyodide we do the following: https://github.com/pyscript/pyscript/blob/aa85f5f5964e61f47b77cac73511d3d74c63328d/pyscriptjs/src/pyodide.ts#L69-L71

Note the return await, which should probably be just a return. I’m not fully sure of the implications of doing the await here but I guess it causes code to be less parallel that it should be.

I think that it means that if we do the following:

await Promise.all([
    runtime.run(src1),
    runtime.run(src2),
    runtime.run(src3)
]);

src1, src2 and src3 will not be executed in parallel but sequentially.

In general, I think we have a problem with our usage of async in our codebase: we use them a bit too freely and without really understanding what’s going on (or at least: personally I don’t fully understand what’s going on: if you do, please explain to me 😃).