revert version updates

Author: ChristianBeilschmidt

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
       fail-fast: false
       matrix:
         # use all supported versions from https://devguide.python.org/versions/
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
 
     with:
       python-version: ${{ matrix.python-version }}