Add tox environment to run tests against packaging 24.0

Author: dnicolodi

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.8
-envlist = lint,types,py{38,39,310,311,312,313},integration,docs
+envlist = lint,types,py{38,39,310,311,312,313}{,-packaging240},integration,docs
 isolated_build = True
 
 [testenv]
@@ -9,6 +9,7 @@ deps =
     pytest
     pytest-socket
     coverage
+    packaging240: packaging==24.0
 passenv =
     PYTEST_ADDOPTS
 setenv =