Youki has changed the way executors are created. The new method is to create a get_executor() function that returns an Executor. The executors in the youki crate can be used as an example: https://github.com/containers/youki/blob/main/crates/youki/src/workload
Instead of the can_handle() function, the executor now returns an ExecutorError::CantHandle(EXECUTOR_NAME) error, which is then handled explicitly like this https://github.com/containers/youki/blob/main/crates/youki/src/workload/executor.rs#L18-L23. This gives more control over the order in which executors are tried.

We need to adapt our executors before upgrading to latest libcontainer version.