Update autograding workflow

Author: github-classroom[bot]

.github/workflows/classroom.yml

@@ -14,6 +14,6 @@ jobs:
     steps:
       - uses: actions/setup-python@v4
         with:
-          python-version: "3.10"
+          python-version: "3.12"
       - uses: actions/checkout@v2
       - uses: education/autograding@v1