Testing works even with newer virtualenv.

--- lazy-1.6/tox.ini.orig
+++ lazy-1.6/tox.ini
@@ -5,7 +5,7 @@
 
 [tox]
 envlist = py27, py36, py37, py38, py39, py310, py311, py312, pypy27, pypy38, mypy
-requires = virtualenv<20.22.0
+requires = virtualenv
 
 [testenv]
 package = wheel