Support Python 3.13 (#495)

Author: joostlek

.github/workflows/tests.yaml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["3.11", "3.12"]
+        python: ["3.11", "3.12", "3.13"]
     steps:
       - name: ⤵️ Check out code from GitHub
         uses: actions/checkout@v4.2.2