Remove driver specification from Buildx setup

Let Buildx use default driver with --privileged container.
The 'docker' driver caused endpoint property errors.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.gitea/workflows/build-deploy.yml

@@ -25,8 +25,6 @@ jobs:
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
-        with:
-          driver: docker
 
       - name: Build and push Docker image
         uses: docker/build-push-action@v6