fix(ci): acr-cleanup改用step_checkout.sh，兼容docker runner

- 替换actions/checkout@v4为curl step_checkout.sh方式
- 删除actions/setup-python@v5（ci-base镜像已自带python3）
- 解决docker runner下setup-python action秒败问题

.gitea/workflows/acr-cleanup.yml

@@ -36,12 +36,11 @@ jobs:
       GITEA_REPO: xiaoxia/xiaoxia-saas
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
-
-      - name: Setup Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
+        shell: sh
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          curl -sH "Authorization: token $GITHUB_TOKEN"             "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/raw/scripts/ci/step_checkout.sh?ref=${GITHUB_SHA}"             | bash
 
       # ====== Cron模式：获取staging运行中镜像作为白名单 ======
       - name: Get staging running images (whitelist)