Add python 3.13 to test matrix

Author: bessman

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13-dev']
 
     steps:
     - uses: actions/checkout@v4

tox.ini

@@ -39,3 +39,4 @@ python =
     3.10: test
     3.11: test
     3.12: test, lint
+    3.13: test, lint