install libreadline

.github/actions/pgx-init/action.yml

@@ -16,6 +16,7 @@ runs:
          mv stoml_linux_amd64 stoml
          chmod +x stoml
          sudo mv stoml /usr/local/bin/
+         apt update && apt install -y libreadline-dev
       - name: setup pgrx
         shell: bash
         id: pgrx_install