update radix sort to latest paradigm

https://github.com/mosure/bevy_gaussian_splatting/blob/7e0a353542add5e21d59083d9033d06dd8d3051a/tests/gpu/radix.rs#L136

```rust

}


// TODO: update radix sort to latest paradigm
impl Node for RadixTestNode {
    fn update(
        &mut self,

```