fixing mypy errors

Author: ipdemes

cunumeric/module.py

@@ -3507,7 +3507,7 @@ def put(
 
 
 @add_boilerplate("a", "mask")
-def putmask(a, mask, values):
+def putmask(a: ndarray, mask: ndarray, values: Any) -> None:
     """
     putmask(a, mask, values)
     Changes elements of an array based on conditional and input values.