build: Add missing buildx steps

Author: TwiN

.github/workflows/publish-latest.yml

@@ -17,6 +17,8 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v3
+      - uses: docker/setup-qemu-action@v2
+      - uses: docker/setup-buildx-action@v2
       - name: Get image repository
         run: echo IMAGE_REPOSITORY=$(echo ghcr.io/${{ github.actor }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
       - name: Login to registry