World::name is always "root"

Hello,

I am following this tutorial:

https://component-model.bytecodealliance.org/language-support/rust.html

Here is my WIT file:

```wit
package example:component;

world example {
// A function to add two 32bit signed integers.
export add: func(x: s32, y: s32) -> s32;
}
```

Yet, `World::name` is apparently set to `"root"` anyway.

Here is the code that loads/decode the WASM component's WIT:

```rust
// Load the WASM module
let module = fs::read(&args.file).expect("Failed to load module");
let wit = wit_component::decode(&module).expect("Failed to decode WIT component");
// Find the exported functions
let functions = wit.resolve().worlds.iter().flat_map(|(_id, world)| {
world.exports.iter().filter_map(|(_, item)| match item {
WorldItem::Function(func) => Some((&world.name, func)),
_ => None,
})
});
```

Am I doing something wrong?