Fix missing loop var usage

src/testing/fixtures.rs

@@ -281,13 +281,12 @@ where
     F: Fn(V) -> Option<u32>,
 {
     let expected = [0, 1, 2, 2, 2, 3, 3, 3, 3, 4];
-    for (i, v) in vertices.iter().enumerate() {
+    for (i, &v) in vertices.iter().enumerate() {
         assert_eq!(
-            actual_for(*v),
+            actual_for(v),
             Some(expected[i]),
-            "unexpected distance from vertex {:?} to vertex {:?}",
-            vertices[0],
-            vertices[i]
+            "unexpected distance from vertex {:?} to vertex {v:?}",
+            vertices[0]
         );
     }
 }