Enhance GitHub Actions workflow by adding QEMU setup and multi-platform support for Docker builds

Author: shyim

.github/workflows/preview.yml

@@ -23,6 +23,9 @@ jobs:
         run: |
           echo "REPO_NAME=$(echo '${{ github.repository }}' | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT
       
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
@@ -38,6 +41,7 @@ jobs:
         with:
           context: .
           push: true
+          platforms: linux/amd64,linux/arm64
           tags: ghcr.io/${{ steps.repo-name.outputs.REPO_NAME }}/pr-${{ github.event.pull_request.number }}:latest
 
       - name: Comment on PR