use new way to get architecture

.gitea/workflows/container.yaml

@@ -6,15 +6,13 @@ jobs:
     steps:
       - name: Check out repository code
         uses: actions/checkout@v3
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v1
       - name: Build image
         id: build-image
         uses: redhat-actions/buildah-build@v2
         with:
           image: docker.io/thallian/alpine-s6
           tags: ${{ gitea.ref_name }} ${{ gitea.sha }} latest
-          archs: amd64
+          archs: amd64, arm64
           containerfiles: |
             ./Containerfile
       - name: Log in to Dockerhub