Update actions/setup-python action to v3

Author: renovate-bot

.github/workflows/build-verify.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python 3.8
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: '3.8'
     - name: Install pybuilder