Run CI tests on Python 3.13

Author: SethMMorton

.github/workflows/tests.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     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"]
         os: [ubuntu-latest]
         extras: [false]
         include: