Disable ruff/refurb rule FURB118

FURB118 Use `operator.add` instead of defining a function

Author: DimitriPapadopoulos

niworkflows/engine/tests/test_plugin.py

@@ -8,7 +8,7 @@
 from ..plugin import MultiProcPlugin
 
 
-def add(x, y):
+def add(x, y):  # noqa: FURB118  # the Function interface does not support builtin functions
     return x + y