start testing with Python 3.13

.github/workflows/run-tests.yml

@@ -21,6 +21,7 @@ on:
   push:
     branches:
       - main
+      - python313
   # run the test only if the PR is to main
   # turn it on if required
   #pull_request:
@@ -39,7 +40,7 @@ jobs:
     runs-on: "ubuntu-latest"
     strategy:
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
       fail-fast: false
     name: Linux Python ${{ matrix.python-version }}
     steps:
@@ -74,7 +75,7 @@ jobs:
     runs-on: "macos-latest"
     strategy:
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
         architecture: ["x64"]  # need to force Intel, arm64 builds have issues
       fail-fast: false
     name: OSX Python ${{ matrix.python-version }}