Latest release of jenkins-job-builder is now attempting to delete old
Jenkins views when updating but this new code triggers an exception when
deploying jobs on our Jenkins instance, so add option --jobs-only to
jenkins-job update command as a workaround to restore previous behavior.

Errors can happen otherwise when executed on a different node.

This was missed when the job was turned to a pipeline one.

For some reason, likely due to the fact that it is a hidden one, that parameter
was not correctly transmitted to the job setting gitlab webhooks and the jenkins
jobs could not be triggered anymore.

Nevertheless, the webhooks job also has the same hidden parameter with the rotated
token as default value so we can safely remove the jenkins_token parameter for the
jenkins-jobs-builder job.

Pass it as a hidden parameter instead as jenkins now requires to manually
validate each groovy script for security concerns.

As a script is identified by the hash of its content, proceeding like
this avoid to revalidate the webhooks setting script each time the token
is rotated.

The old job would trigger the jobs update on a merge request with source
branch "master", e.g. from a fork.

We need to checkout the branch merge-requests/${env.gitlabMergeRequestIid}
in that case.

This code snippet is used in numerous Jenkins pipelines so better
deduplicating it.

SWH migration to GitLab is incoming and we are not using elastic workers
yet in production so we still need to build debian packages for swh modules.

So add support for building the debian packages when pushing tags to swh
module repositories hosted on GitLab.

This job is responsible to setup the webhooks on swh GitLab repositories
enabling to trigger Jenkins builds when pushing changes or creating merge
requests.

It parses Jenkins jobs builder YAML configuration to get the name of the
repos with CI setup and set webhook URLs in GitLab projects through HTTP
requests to the GitLab REST API.

It is triggered at the end of the swh-jenkins-jobs-builder job after jobs
have been reconfigured.

This job is responsible of updating the Jenkins jobs configuration
when executed. It will be triggered when pushing changes to the
swh-jenkins-jobs repository.

When triggered from a GitLab merge request, Jenkins jobs configuration
is not updated, only proper jobs generation is checked.