Add Python 3.13 CI to GitHub Actions

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12"]
+        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12", "3.13"]
         os: [ubuntu-latest, macos-latest]
     steps:
     - uses: actions/checkout@v3
@@ -35,6 +35,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
         cache: 'pip'
         cache-dependency-path: setup.py
+        allow-prereleases: true
     - name: Install dependencies
       run: |
         python -m pip install -U pip setuptools wheel