fix(cicd): use python container instead of setup-python action

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -11,20 +11,14 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    container:
+      image: python:3.12-slim
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Setup Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
-          check-latest: true
-          cache: 'pip'
-
       - name: Install dependencies
-        run: |
-          pip install ansible ansible-bundler
+        run: pip install ansible ansible-bundler
 
       - name: Verify playbook syntax
         run: |