fix: give buildx builder host networking so it can reach localhost:5000

.gitea/workflows/docker.yml

@@ -45,6 +45,8 @@ jobs:
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+        with:
+          driver-opts: network=host
 
       # Start a local registry so BuildKit can push multi-platform images
       # without hitting Gitea's broken Bearer token endpoint. regctl then