Fix redbear-sessiond Redox shutdown: remove unreachable code after tokio::select!

The #[cfg(target_os = "redox")] variant of wait_for_shutdown had dead code
after the tokio::select! block. The select already returns Result<(), _>, so
the trailing Ok(()) was unreachable and caused a type mismatch when the compiler
tried to coerce the select result into (). Remove the dead code.

local/recipes/system/redbear-sessiond/source/src/main.rs

@@ -102,8 +102,6 @@ async fn wait_for_shutdown(mut shutdown_rx: tokio::sync::watch::Receiver<bool>)
         _ = std::future::pending::<()>() => Ok(()),
         _ = shutdown_rx.changed() => Ok(()),
     }
-    #[allow(unreachable_code)]
-    Ok(())
 }
 
 #[cfg(all(not(unix), not(target_os = "redox")))]