Run tests against Python 3.12 and add trove classifier

According to https://docs.python.org/3.12/whatsnew/3.12.html,
setuptools is no longer installed by default in virtual environments:

    gh-95299: Do not pre-install setuptools in virtual environments
    created with venv. This means that distutils, setuptools,
    pkg_resources, and easy_install will no longer available by
    default; to access these run pip install setuptools in the
    activated virtual environment.

Therefore we have to add it as a dependency to tox.ini.

.github/workflows/tests.yml

@@ -20,6 +20,7 @@ jobs:
         - "3.9"
         - "3.10"
         - "3.11"
+        - "3.12"
 
     steps:
       - uses: actions/checkout@v3

setup.cfg

@@ -21,6 +21,7 @@ classifiers =
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
 project_urls =
     Changelog = https://github.com/cloudtools/awacs/blob/master/CHANGELOG.md
     Source = https://github.com/cloudtools/awacs

tox.ini

@@ -1,9 +1,11 @@
 [tox]
 envlist =
-    py{36,37,38,39,310,311}
+    py{36,37,38,39,310,311,312}
     qa,package
 
 [testenv]
+deps =
+    setuptools
 commands = python -W error::PendingDeprecationWarning setup.py test {posargs}
 
 [testenv:mypy]