Add Python 3.13 CI builds

Author: miguelgrinberg

.github/workflows/tests.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, macos-latest, ubuntu-latest]
-        python: ['pypy-3.10', '3.8', '3.9', '3.10', '3.11', '3.12']
+        python: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13', 'pypy-3.10']
         exclude:
           # pypy3 currently fails to run on Windows
           - os: windows-latest

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist=flake8,py{38,39,310,311,312,py3},docs
+envlist=flake8,py{38,39,310,311,312,313},docs
 skip_missing_interpreters=True
 
 [gh-actions]
@@ -9,6 +9,7 @@ python =
     3.10: py310
     3.11: py311
     3.12: py312
+    3.13: py313
     pypy-3: pypy3
 
 [testenv]