test: assert reference script size

Add assertion to verify that the reference script size returned by `get_ref_script_size` matches expected values.

Author: mkoura

cardano_node_tests/tests/tests_plutus_v2/test_mint_build.py

@@ -244,6 +244,16 @@ def test_minting_ref_one_token(
             expected_costs=[script_expected_fee["cost"]],
         )
 
+        ref_size = cluster.g_query.get_ref_script_size(utxo=reference_utxo)["refInputScriptSize"]
+        expected_sizes = {
+            "v2": 1893,
+            "v3": 6,
+        }
+        expected_size = expected_sizes[plutus_version]
+        assert ref_size == expected_size, (
+            f"Unexpected reference script size: expected {expected_size}, got {ref_size}"
+        )
+
     @allure.link(helpers.get_vcs_link())
     @common.PARAM_PLUTUS2ONWARDS_VERSION
     @pytest.mark.smoke