let's try this again...

ci/push-package.template.yml

@@ -5,8 +5,9 @@
       - mkdir -p ~/.ssh
       - 'command -v ssh-agent >/dev/null || ( apt-get update -y && apt-get install openssh-client -y )'
       - eval $(ssh-agent -s)
-      - chmod 400 "$SSH_PRIVATE_KEY"
-      - ssh-add "$SSH_PRIVATE_KEY"
+      - echo $SSH_PRIVATE_KEY > .ssh/id_ed25519
+      - chmod 400 .ssh/id_ed25519
+      - ssh-add .ssh/id_ed25519
       - chmod 700 ~/.ssh
       - '[[ -f /.dockerenv ]] && echo -e "Host *\\n\\tStrictHostKeyChecking no\\n\\n" > ~/.ssh/config'
     script: