Given a job being configured, when a user enters a ssh clone url for a new server, the validation form will complain about Host key verification failed..
Usually the user will then configure a set of credentials. If they are correct, the validation will succeed. If they are incorrect, the error will be Permission denied (publickey).

The current implementation currently pass StrictHostKeyChecking=no as soon as some SSH credentials are provided, but not when no (or non-ssh) credentials are provided. It will then lead to this inconsistent error message which misleads the user into thinking something is wrong with the known_hosts file.

In a freestyle job context this is usually very minor as the validation will provide a quick fail, however in a workflow context where the configuration is provided through free text or from scm, this can lead to confusion.

Therefore, I'm proposing to provide this option to every ssh call through git, so that the error message is consistent.