keep fixing CI 3

.gitea/workflows/backend-docker.yml

@@ -16,7 +16,8 @@ jobs:
     runs-on: docker
     container:
       image: debian:bookworm-slim
-      options: --privileged -v /var/run/docker.sock:/var/run/docker.sock
+      # act_runner already mounts the Docker socket; avoid duplicating it
+      options: --privileged
     steps:
       - name: Prepare tools via Tencent mirrors (apt)
         shell: bash