Tweak Image classes table cycle detection

Author: AlexKnauth

src/game_engine/unity/mono.rs

@@ -332,11 +332,9 @@ impl Image {
                 .unwrap_or_default();
 
             iter::from_fn(move || {
-                #[cfg(feature = "alloc")]
-                if seen.contains(&table) { return None; }
                 if !table.is_null() {
                     #[cfg(feature = "alloc")]
-                    seen.insert(table);
+                    if seen.replace(table).is_some() { return None; }
                     let class = module.read_pointer(process, table).ok()?;
                     table = module
                         .read_pointer(