add arm builds

Author: brosner

.github/workflows/ci.yml

@@ -94,6 +94,7 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           annotations: ${{ steps.meta.outputs.annotations }}
           target: prod
+          platforms: linux/amd64,linux/arm64
           load: true
           cache-from: type=gha
           cache-to: type=gha,mode=max