python 3.9 in workflow

.github/workflows/code_checks.yml

@@ -15,10 +15,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - name: Set up Python 3.7.4
+      - name: Set up Python 3.9
         uses: actions/setup-python@v4
         with:
-          python-version: "3.7.4"
+          python-version: "3.9"
       - name: Install dependencies
         run: |
           pip install isort==5.10.1 black[jupyter]==22.3.0

.github/workflows/doc.yml

@@ -17,7 +17,7 @@ jobs:
           submodules: 'recursive'
       - uses: actions/setup-python@v3
         with:
-          python-version: '3.8.12'
+          python-version: '3.9'
       - name: Install dependencies
         run: |
           pip install -r docs/requirements.txt