update action

Author: reliveyy

.github/workflows/ci.yml

@@ -19,5 +19,12 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Checkout
         uses: actions/checkout@v2
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.9'
+          architecture: 'x64'
+      - name: Show Python version
+        run: python -c "import sys; print(sys.version)"
       - name: Build and push
         run: tools/build utils && tools/push utils