Latest docker build tag should not be use in production and staging deployment

Docker image build in staging mode sets a tag with latest.

https://gitlab.eclipse.org/eclipsefdn/it/api/eclipsefdn-committer-paperwork-api/-/blob/main/Jenkinsfile?ref_type=heads#L178

This is dangerous because the `latest tag is used in Kubernetes deployment for production and staging. So, at any time, Kubernetes can decide to deploy a staging pod into production.

I propose to rename latest tag for staging and use something like latest-staging.