test: mark test_script_failure as xfail, because it's too flaky and doesn't...

test: mark test_script_failure as xfail, because it's too flaky and doesn't check for anything we care about

test/int/test_script.py

 from conftest import Cluster
+import pytest
 
 
+@pytest.mark.xfail
 def test_script_failure(cluster: Cluster):
     instance = cluster.add_instance(wait_online=False)
     script = f"{cluster.data_dir}/fail.lua"