Update python/pyarrow-stubs/_compute.pyi

Co-authored-by: Dan Redding <125183946+dangotbanned@users.noreply.github.com>

Author: rok

python/pyarrow-stubs/_compute.pyi

@@ -41,7 +41,7 @@ class Kernel(lib._Weakrefable):
 
 class Function(lib._Weakrefable):
     @property
-    def arity(self) -> int: ...
+    def arity(self) -> int | EllipsisType: ...
 
     @property
     def kind(