add setdiff1d to xpx module

Author: lucascolley

src/array_api_extra/__init__.py

@@ -1,15 +1,17 @@
 from __future__ import annotations
 
-from ._funcs import atleast_nd, cov, create_diagonal, expand_dims, kron, sinc
+from ._funcs import atleast_nd, cov, create_diagonal, expand_dims, kron, setdiff1d, sinc
 
 __version__ = "0.2.1.dev0"
 
+# pylint: disable=duplicate-code
 __all__ = [
     "__version__",
     "atleast_nd",
     "cov",
     "create_diagonal",
     "expand_dims",
     "kron",
+    "setdiff1d",
     "sinc",
 ]