fix: if the commitment is not available we return zero

verkle-trie/src/proof/verifier.rs

@@ -202,7 +202,10 @@ pub fn create_verifier_queries(
         child_path.push(*z);
         let y = match leaf_values_by_path_and_z.get(&(path.clone(), *z)) {
             Some(val) => *val,
-            None => group_to_field(&commitments_by_path[&child_path]),
+            None => match commitments_by_path.get(&child_path) {
+                Some(commitment_by_path) => group_to_field(&commitment_by_path),
+                None => Fr::zero(),
+            },
         };
 
         ys_by_path_and_z.insert((path.clone(), *z), y);