Fix special case when key expires in between the checks of the public and privat...

[github-actions]

keys. Suggestion: allow a couple of retries.

https://api.github.com/elixir-europe/crypt4gh-recryptor-service/blob/581ca1c075db334fcfae6357bfbf3e1d1dae2a50/src/crypt4gh_recryptor_service/compute.py#L51

            settings.private_key_comment,
            verbose=settings.dev_mode)
    elif existing_key_files == 1:
        # TODO: Fix special case when key expires in between the checks of the public and private
        #       keys. Suggestion: allow a couple of retries.
        raise Exception('Only one of the compute node public/private keypair files exists!'
                        f' Key id: {compute_public_key_file.key_id}')
    else: