Bug: rust program fails to compile due to type errors in example

[ifsheldon]

https://github.com/codelion/openevolve/blob/897cb78d5880433d9e545a4da002656d1926cf20/examples/rust_adaptive_sort/evaluator.py#L55

The Rust program here fails to compile due to type conversion errors. Specifically, the simple random function needs T: From<u64>, but many integer types do not have this trait impl, like i32.