This introduces a new variable node which allows to either run it on the built-in
node (like actually with the production jenkins) or on the 'docker' agent node (which
should be configured either prior to choose it).

This is actually useful for running in a local jenkins and hacking around those jobs.
This will also allow further developement on similar jobs which requires to run docker.
For example, the future build-docker-images.

This also drops the instruction `updateGitlabCommitStatus` which is not needed in that
job (since that won't be opened in a mr context).

Ref. swh/infra/sysadm-environment#4724

With a potential docker agent.

Some docker jobs can run directly on the host machines but some cannot. The ones
requiring some mount points to be passed along for example. In that case, the docker
agent is preferred.

Ref. swh/infra/sysadm-environment#4724

When testing jobs on a local Jenkins server, disable the cron triggers
and prefer to run jobs manually.

Related to !176.

Add production_jenkins global variable indicating if we are generating jobs
for production Jenkins based on the value of the current hostname.

It enables to remove or add some settings when generating jobs for a local
jenkins server used for testing.

Related to !176.

(if we want to keep it, it should be reintroduced as a tox config)

This reverts commit 9ebd1dc8.

The cypress team recently put effort to block the use of sorry-cypress,
an open source tests orchestrator for cypress. Fortunately, the sorry-cypress
team created cypress-cloud, a new tool designed to bypass those restrictions.

So use the tool in our pipeline for swh-web.

This is redundant with the "Gitlab builds" triggers so only keep the
daily cron trigger for that job.

They will not be deployed through Debian packages, no need to bother
with building them.

Previously, merge requests were also rebuilt when pushing to the target
branch which is not required.

The subversion loader now includes a C++ extension module so only generate
source distribution for PyPI upload as the binary wheel needs to be generated
on a dedicated docker image then repaired with the auditwheel tool.

So until our Jenkins pipeline supports building and repairing binary wheels
for linux platform, disable the binary wheel generation for swh-loader-svn.

Since recently, merge requests are not rebuilt by Jenkins when pushing
new commits to it. This could be related to some default configuration
changes in latest release of GitLab plugin for Jenkins.

As that behavior is not enabled by default in gitlab trigger settings
explicitly enable it in jenkins jobs configuration.

See https://storyboard.openstack.org/#!/story/2010752

The tests for swh-webhooks rely on docker-compose and currently cannot
be executed by multiple jobs in parallel due to the way our jenkins
pipelines are configured.

So ensure only one job can be executed at a time to avoid race conditions.

More efficient in regards to our current way of building some specific images which are
growing forever (up until we got no more disk space on thyssen).
That's a simpler workaround than what's discussed in issue [1] [2]. We keep the last "2"
days images so the next build still benefits from it but we drop the rest (so no more
too much disk cost). As this job is triggered daily, that should keep those images in
check.

Provided, the following script is installed on the node:

```
$ root@thyssen:~# cat /usr/local/bin/clean-docker-images.sh

set -x

today=$(date --date '13:00' +%Y%m%d)
yesterday=$(date --date 'yesterday 13:00' +%Y%m%d)

images_to_drop=$(docker image ls \
    | grep -E "softwareheritage/(base|web|replayer)" \
    | grep -v $today \
    | grep -v $yesterday \
    | grep -v "latest")

if [ ! -z "$images_to_drop" ]; then
    echo $images_to_drop \
    | awk '{print $1":"$2}' \
    | xargs docker rmi
fi

docker system prune --filter 'label!=keep' --volumes --force
```

Refs. swh/infra/sysadm-environment#4846

[1] swh/infra/sysadm-environment#4848

[2] swh/infra/sysadm-environment#4846

Previously, we kept them up to 90 days but this quickly eats significant
disk space on the jenkins host as the full HTML documentation for SWH is
published as a report for each build triggered from GitLab.

Related to swh/infra/sysadm-environment#4846

SWH documentations have been merged into a single one so we can now remove
these publish HTML steps.

Refs. swh/infra/sysadm-environment#4766

Refs. swh/infra/sysadm-environment#4766

Refs. swh/infra/sysadm-environment#4766

Related to swh/devel/swh-web#4734

It enables a better selection of the git branch to checkout when
dealing with gilab merge requests.

It enables to test proper build of docker images when their dockerfiles
are modified without impacting the images used by our Jenkins jobs.

This also adapts to use the proper check as the previous check implemented always
returned false (without an absolute path that is).

Refs. swh/infra/sysadm-environment#4524