Fix (ci): Drop support for linux/390x

Author: leojonathanoh

.github/workflows/ci-master-pr.yml

@@ -147,7 +147,7 @@ jobs:
         file: Dockerfile
         context: '.'
         target: prod
-        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/s390x
+        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
         push: true
         tags: ${{ steps.meta.outputs.tags }}
         cache-from: type=local,src=/tmp/.buildx-cache-asp