Add Python 3.12 to envlist

Author: ymyzk

setup.cfg

@@ -86,7 +86,7 @@ skip_missing_interpreters = true
 envlist =
     black
     flake8
-    {py27,py35,py36,py37,py38,py39,py310,py311,pypy2,pypy3}-tox{312,315,latest}
+    {py27,py35,py36,py37,py38,py39,py310,py311,py312,pypy2,pypy3}-tox{312,315,latest}
 
 [gh-actions]
 python =
@@ -98,6 +98,7 @@ python =
     3.9: py39
     3.10: py310
     3.11: py311
+    3.12: py312
     pypy-2: pypy2
     pypy-3: pypy3