fix: use docker driver for buildx on debian-host runner

docker-container driver (default) tries to spin up a BuildKit
container which can fail on host runners. 'driver: docker' uses
the host daemon directly — simpler and more reliable.

.gitea/workflows/deploy.yml

@@ -35,6 +35,8 @@ jobs:
 
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v3
+      with:
+        driver: docker
       env:
         PATH: /usr/bin:/usr/local/bin:/bin:/sbin:/usr/sbin