Add Python 3.13 to tests

https://peps.python.org/pep-0719/

Author: daveisfera

.github/workflows/main.yml

@@ -23,7 +23,7 @@ jobs:
       # You can use PyPy versions in python-version.
       # For example, pypy2 and pypy3
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps: