Update Python version to 3.11 in GitHub workflow

.github/workflows/CI.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.7
+    - name: Set up Python 3.11
       uses: actions/setup-python@v2
       with:
-        python-version: 3.7
+        python-version: 3.11
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip