ci: update Python ver. to 3.10 in GitHub Actions

.github/workflows/python-app.yml

@@ -19,10 +19,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - name: Set up Python 3.9
+    - name: Set up Python 3.10
       uses: actions/setup-python@v4
       with:
-        python-version: "3.9"
+        python-version: "3.10"
         cache: "pip"
     - name: Install dependencies
       run: |