refactor: do not test for boolean with is

Author: LukeSavefrogs

src/polyfills/stdlib/functions.py

@@ -133,7 +133,7 @@ def cmp(a, b):
                 # Convert the key function to a cmp function, since the `key` argument is not available.
                 elements.sort(key_to_cmp(key))
 
-        if reverse is True:
+        if reverse:
             elements.reverse()
 
         value = []