fix(gix-diff): adapt to changes in gix-object

Author: pierrechevalier83

gix-diff/src/tree/visit.rs

@@ -161,8 +161,8 @@ mod tests {
     fn size_of_change() {
         let actual = std::mem::size_of::<Change>();
         assert!(
-            actual <= 48,
-            "{actual} <= 48: this type shouldn't grow without us knowing"
+            actual <= 60,
+            "{actual} <= 60: this type shouldn't grow without us knowing"
         );
     }
 }