Address soundness hole in cycle prevention

tests/runtimes/smol.rs

@@ -26,7 +26,7 @@ fn test_basic_dag_smol() {
 
         let x = dag.add_task(Value(2));
         let y = dag.add_task(Value(3));
-        let sum = dag.add_task(Add).depends_on((&x, &y));
+        let sum = dag.add_task(Add).depends_on((x, y));
 
         dag.run(smol::spawn).await.unwrap();
 
@@ -45,7 +45,7 @@ fn test_parallel_execution_smol() {
 
         dag.run(smol::spawn).await.unwrap();
 
-        for (i, task) in tasks.iter().enumerate() {
+        for (i, task) in tasks.into_iter().enumerate() {
             assert_eq!(dag.get(task).unwrap(), i * 2);
         }
     });
@@ -58,7 +58,7 @@ fn test_complex_dependencies_smol() {
 
         let a = dag.add_task(Value(10));
         let b = dag.add_task(Value(20));
-        let sum = dag.add_task(Add).depends_on((&a, &b));
+        let sum = dag.add_task(Add).depends_on((a, b));
         let double = dag
             .add_task(task_fn(|x: i32| async move { x * 2 }))
             .depends_on(sum);