Use apt to install Python modules for actions

.forgejo/workflows/build.yaml

@@ -42,8 +42,7 @@ jobs:
           cache: pip
       - name: Set up Python environment
         run: |
-          curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
-          python3 get-pip.py
+          apt-get install python3-pip python3-setuptools python3-wheel python3-venv
           python3 -m venv venv
           source venv/bin/activate
           pip install -r requirements.txt