Update src/sage/combinat/integer_vector_weighted.py

Co-authored-by: Matthias Köppe <mkoeppe@math.ucdavis.edu>

src/sage/combinat/integer_vector_weighted.py

@@ -185,7 +185,7 @@ def __contains__(self, x):
             return False
         s = 0
         for i, xi in enumerate(x):
-            if (not isinstance(xi, (int, Integer))) and (xi not in ZZ):
+            if not isinstance(xi, (int, Integer)) and xi not in ZZ:
                 return False
             s += xi * self._weights[i]
         return s == self._n