Add 'docker logout' after 'docker login' to CI pipeline

When logging in to a registry, Docker save credentials in its configuration file.

But in CI jobs, the credentials used are the CI job tokens, and these are invalidated once the job is over. This causes issues when Docker tries to reuse these invalid credentials in other jobs.

In order for the credentials to be removed from the configuration file at the end of each job, it is necessary to add the docker logout docker.opencarp.org statement as a postscript command if a login to the registry was made in the job.