Bug: async function evaluate in Rust adaptive sort example

[ifsheldon]

https://github.com/codelion/openevolve/blob/897cb78d5880433d9e545a4da002656d1926cf20/examples/rust_adaptive_sort/evaluator.py#L19

Here the function is async, but openevolve only accepts sync functions, so there will be errors like Unexpected evaluation result type: <class 'coroutine'>.