fix: use unix socket for docker buildx context on debian-host runner

The TCP docker context (tcp://docker:2376/) is for DinD runners.
debian-host uses the host unix socket directly.

.gitea/workflows/deploy.yml

@@ -27,10 +27,8 @@ jobs:
     - name: Set up Docker Context for Buildx
       id: buildx-context
       run: |
-        export DOCKER_HOST=tcp://docker:2376/
-        export DOCKER_TLS_VERIFY=0
-        docker context rm builders || true
-        docker context create builders
+        docker context rm builders 2>/dev/null || true
+        docker context create builders --docker host=unix:///var/run/docker.sock
 
     - name: Verify Docker
       run: docker --version