fix(cicd): installing pip directly fuck setup-python

.gitea/workflows/build.yml

@@ -15,11 +15,9 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Setup Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
-          cache: 'pip'
+      - name: Install Python
+        run: |
+          apt-get update && apt-get install -y python3 python3-pip
 
       - name: Install dependencies
         run: |