Use Python container for CI

.gitea/workflows/ci.yml

@@ -4,17 +4,13 @@ on: [push, pull_request]
 jobs:
   test:
     runs-on: ubuntu-latest
+    container: python:3.11-slim
     steps:
       - name: Checkout code
         run: |
-          mkdir -p /tmp/man-card
-          cd /tmp/man-card
-          git init
-          git remote add origin https://7000pct.gitea.bloupla.net/7000pctAUTO/man-card.git
-          git fetch --depth 1 origin main
-          git checkout main
+          git clone --depth 1 https://7000pct.gitea.bloupla.net/7000pctAUTO/man-card.git /tmp/man-card
 
-      - name: Install and run tests
+      - name: Install and test
         run: |
           cd /tmp/man-card
           pip install --quiet click fpdf2 Pillow rich python-dotenv pytest pytest-cov