Add ARM64 platform support to GitHub Container Registry builds

Co-authored-by: commjoen <[email protected]>

Author: Copilot

.github/workflows/preview.yml

@@ -71,7 +71,7 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          platforms: linux/amd64
+          platforms: linux/amd64,linux/arm64
 
   generate-preview-instructions:
     name: "Generate Preview Instructions"