fix(wavl): do not check for v if not needed

Signed-off-by: Matej Focko <mfocko@redhat.com>

wavl.py

@@ -50,7 +50,7 @@ class WAVLTree(AVLTree[T]):
         w_diff = Node.difference(w, y)
         logger.debug(f"w_diff = {w_diff}")
 
-        assert v
+        # assert v
         if w_diff == 1 and y.parent:
             logger.debug(f"y.parent = {y.parent}")
             new_root = rotate_left(y.parent)