Fixed cleanup step for release process (#2002)

.github/workflows/release-post-merge.yml

@@ -70,7 +70,7 @@ jobs:
           sudo swapoff -a
           sudo rm -f /swapfile
           sudo apt clean
-          docker rmi $(docker image ls -aq)
+          docker rmi $(docker image ls -aq) &> /dev/null || true
           df -h
       - name: Compute release tag and options
         id: tag