feat: fix GitHub Action (#89)

* feat: fix GitHub Action

* feat: fix GitHub Action

.github/workflows/default.yml

diff --git a/.github/workflows/default.yml b/.github/workflows/default.yml
index 739af67..d15a195 100644
--- a/.github/workflows/default.yml
+++ b/.github/workflows/default.yml
@@ -69,6 +69,15 @@
           
           fi
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v2
+        with:
+          version: latest
+
       - name: Log in to Docker Hub
         uses: docker/login-action@v1
         if: github.repository == 'casbin/casbin-server' && github.event_name == 'push' && steps.should_push.outputs.push=='true'