Add py312 to tox.ini (#2382)

Author: wbarnha

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{38,39,310,311,py}, docs
+envlist = py{38,39,310,311,312,py}, docs
 
 [pytest]
 testpaths = kafka test
@@ -12,6 +12,7 @@ python =
     3.9: py39
     3.10: py310
     3.11: py311
+    3.12: py312
     pypy-3.9: pypy
 
 [testenv]