docker-login plugin does not logout

[fiedlerdemos]

In my pipeline.yml I used:
- docker-login#v2.1.0:
username: xxxx
password-env: MY_DOCKER_LOGIN_PASSWORD
Every thing ok.
But after termination of pipeline in /var/lib/buildkite-agent/.docker/config.json remains with authentication information and not empty as it would be after appropriate logout.
So everyone using this agent can manipulate docker repos.

[toote]

@fiedlerdemos that is actually a great find and points to a deeper issue when an instance has several agents as well. I will see what can be done about it