Try to lock python version in github actions

.github/workflows/build_and_test.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set-up Python
       uses: actions/setup-python@v1
       with:
-        python-version: '3.x'
+        python-version: '3.10'
     - name: Set-up latest pip
       run: |
         python -m pip install --upgrade pip