fix: build multi-arch image

.github/workflows/legacy-proxy.yml

@@ -7,10 +7,13 @@ jobs:
   build-and-push:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v4
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v3
     - name: Set up Docker Buildx
-      uses: docker/setup-buildx-action@v2
+      uses: docker/setup-buildx-action@v3
     - name: Login to GitHub Container Registry
-      uses: docker/login-action@v2
+      uses: docker/login-action@v3
       with:
         registry: ghcr.io
         username: ${{ github.repository_owner }}
@@ -25,6 +28,7 @@ jobs:
       uses: docker/build-push-action@v3
       with:
         file: ./legacy-proxy/Dockerfile
+        platforms: linux/amd64,linux/arm64
         push: true
         tags: ghcr.io/${{github.repository}}-legacy-proxy:v1_${{steps.hash.outputs.hash}}_${{steps.datetime.outputs.datetime}}
         cache-from: type=gha