feat(tests): mark plutusv3 builtins test as long

Add the @pytest.mark.long decorator to the test_plutusv3_builtins test in
test_mint_build.py. This allows the test suite to identify and optionally
exclude long-running tests during execution.

Author: mkoura

cardano_node_tests/tests/tests_plutus_v3/test_mint_build.py

@@ -184,6 +184,7 @@ def run_scenario(
         assert token_utxo and token_utxo[0].amount == token_amount, "The token was not minted"
 
     @allure.link(helpers.get_vcs_link())
+    @pytest.mark.long
     @pytest.mark.team_plutus
     def test_plutusv3_builtins(
         self,