Fix testworkflow

[josecelano]

Error: https://github.com/Nautilus-Cyberneering/nautilus-librarian/actions/runs/5953384611/job/16147509865?pr=118#step:3:1

The test workflow is failing because it can import the GPG key.

Run crazy-max/ghaction-import-gpg@v4
  with:
    git_config_global: true
    git_user_signingkey: true
    git_commit_gpgsign: true
    git_tag_gpgsign: false
    git_push_gpgsign: if-asked
    workdir: .
Warning: The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/[2](https://github.com/Nautilus-Cyberneering/nautilus-librarian/actions/runs/5953384611/job/16147509865?pr=118#step:3:2)022-[10](https://github.com/Nautilus-Cyberneering/nautilus-librarian/actions/runs/5953384611/job/16147509865?pr=118#step:3:11)-11-github-actions-deprecating-save-state-and-set-output-commands/
Error: Input required and not supplied: gpg_private_key