refactor setup_many_unchained_txs

- Fix the test setup for many unchained txs

[Ticket: X]

crates/chain/benches/canonicalization.rs

@@ -332,9 +332,8 @@ fn setup_many_chained_unconfirmed(
                     0,
                 )]
             },
-            outputs: vec![TxOutTemplate::new(Amount::ONE_BTC.to_sat(), Some(1))],
-            anchors: vec![],
             last_seen: Some(i as u64),
+            ..Default::default()
         });
     }
 
@@ -363,14 +362,14 @@ fn setup_nested_conflicts(
     for depth in 1..=graph_depth {
         let mut next_outputs = Vec::new();
 
-        for previous_output_name in previous_outputs.drain(..) {
+        for (parent_index, previous_output_name) in previous_outputs.drain(..).enumerate() {
             for conflict_i in 1..=conflicts_per_output {
-                let tx_name = format!("depth_{}_conflict_{}", depth, conflict_i);
+                let tx_name = format!(
+                    "depth_{}_parent_{}_conflict_{}",
+                    depth, parent_index, conflict_i
+                );
 
-                let mut last_seen = depth * conflict_i;
-                if last_seen % 2 == 0 {
-                    last_seen /= 2;
-                }
+                let last_seen = depth as u64 * conflict_i as u64;
 
                 templates.push(TxTemplate {
                     tx_name: tx_name.clone().into(),
@@ -380,7 +379,7 @@ fn setup_nested_conflicts(
                         Some(0),
                     )],
                     anchors: vec![],
-                    last_seen: Some(last_seen as u64),
+                    last_seen: Some(last_seen),
                 });
 
                 next_outputs.push(tx_name);