Replace 3.12-dev with 3.12 and 'allow-prereleases: true'

Author: hugovk

.github/workflows/tests.yml

@@ -13,14 +13,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12-dev"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
+          allow-prereleases: true
           cache: pip
           cache-dependency-path: .github/workflows/tests.yml
       - name: Upgrade pip