workflow: Build for both arm and amd archs

Author: devadathanmb

.github/workflows/build-and-push.yml

@@ -30,5 +30,5 @@ jobs:
       run: |
         # Ensure the builder supports multi-architecture
         docker buildx create --use
-        # Build and push image only for arm64
-        docker buildx build --platform linux/arm64 -t devadathanmb/ktu-bot:latest --push .
+        # Build for both platforms and push
+        docker buildx build --platform linux/amd64,linux/arm64 -t devadathanmb/ktu-bot:latest --push .