Update CI to use Python 3.12

Author: m-messer

.github/workflows/test-lint.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8"]
+        python-version: ["3.12"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4