fix: Use pedersen_hash for merkle tree (#3357)

Co-authored-by: Tom French <15848336+TomAFrench@users.noreply.github.com>

noir_stdlib/src/merkle.nr

@@ -14,8 +14,7 @@ pub fn compute_merkle_root<N>(leaf: Field, index: Field, hash_path: [Field; N])
          } else {
             (current, hash_path[i])
          };
-    // TODO(Kev): This should be changed to use pedersen_hash
-      current = crate::hash::pedersen_commitment([hash_left, hash_right])[0];
+      current = crate::hash::pedersen_hash([hash_left, hash_right]);
     };
     current
 }

tooling/nargo_cli/tests/execution_success/merkle_insert/Prover.toml

@@ -1,11 +1,11 @@
-old_root = "0x200fbe381993186866de8eb5a9cc33845de6b084be3ff67f6e34d35b8a786157"
-old_leaf = "0x1cdcf02431ba623767fe389337d011df1048dcc24b98ed81cec97627bab454a0"
+old_root = "0x2131c74af6250d1246797588ff075b672e3d2e6805f9c6b313ade8f6b9e12802"
+old_leaf = "0x2df8b940e5890e4e1377e05373fae69a1d754f6935e6a780b666947431f2cdcd"
 old_hash_path = [
-    "0x1cdcf02431ba623767fe389337d011df1048dcc24b98ed81cec97627bab454a0",
-    "0x0b5e9666e7323ce925c28201a97ddf4144ac9d148448ed6f49f9008719c1b85b",
-    "0x22ec636f8ad30ef78c42b7fe2be4a4cacf5a445cfb5948224539f59a11d70775",
+    "0x03542cb720369f19a74fd05b4edfbedb27a78514ad3283f1b3270a1656cced8e",
+    "0x1278272f6e617666b18c52349c4bbe94249a8ab59add2ee0a142168a92b7ffc2",
+    "0x2547cfd7699ad1f331fb77b30a3445c6043a4c62b5b1215356b2924607bf937b",
 ]
-new_root = "0x029ead881a6684995190589a67874f188f33a433211df82f56c1351c96530387"
-leaf = "0x085ca53be9c9d95b57e6e5fc91c5d531ad9e63e85dd71af7e35562991774b435"
+new_root = "0x25e2a8ee5b85e5b546ae27832b9b53f5fae5b371e3e7f8cddda839f41669fc68"
+leaf = "0x23fe6c8f2426b793f0f156f57efbecbea52e951af761634a85e80cc1a9fb5003"
 index = "0"
 mimc_input = [12, 45, 78, 41]

tooling/nargo_cli/tests/execution_success/simple_shield/Prover.toml

@@ -1,6 +1,6 @@
 # Random test key
 priv_key = "0x000000000000000000000000000000000000000000000000000000616c696365"
-note_root = "0x0f8cd7b45fbb4e08f63126f1673ce9e574cfbda70f36c2e5182f9e3dbe6524c0"
+note_root = "0x02278fc806225cd696bd502049f7bb98624536de56d09343f8a26ac1876b23a0"
 index = "0"
 note_hash_path = [
     "0x1cdcf02431ba623767fe389337d011df1048dcc24b98ed81cec97627bab454a0",