RunningProgress can't be Clone, since it will panic on the second drop.

When dropping, we remove the key from hash table and panic if it's not there.

crates/maelstrom-client-process/src/progress.rs

@@ -36,7 +36,7 @@ where
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct RunningProgress {
     name: String,
     progress: Arc<AtomicU64>,