Increase MAX_DESCENDANTS_DEPTH to 3 in the CI / CD

Proposal

Hello, we would like to propose an increase of the variable MAX_DESCENDANTS_DEPTH to 3 in the CI / CD. The current value is 2 and is not suitable for our use case. We therefore have the error "reached maximum dephth of child pipelines".

We use templates to generate our web configuration. The value of 2 works great when we only manage our extranet, but when we decide to add our intranet to the same repository, we add an extra level and our pipeline fails. We can avoid this extra level but the use of include in the trigger does not allow to use * in the paths (but that is another story).

Examples:

# Example for gitlab-ci.yml
build:
  stage: build
  script:
    - generate-build-by-hosts.py
  artifacts:
    paths:
      - extra.yml
      - intra.yml
pools:
  stage: trigger
  trigger:
    include:   
      - artifact: extra.yml
        job: build
      - artifact: intra.yml
        job: build
#
# Example for extra.yml (intra.yml is similar)
build:
  stage: build
  script:
    - generate-build-by-domains.py # create the domains.yml file with each domain in a pipeline 
  artifacts:
    paths:
      - domains.yml
domains:
  stage: trigger
  trigger:
    include:   
      - artifact: domains.yml
        job: build
#
## Not possible to avoid creating the domains.yml file 
build:
  stage: build
  script:
    - generate-build-by-domains.py
  artifacts:
    paths:
      - domains-*.yml
domains:
  stage: trigger
  trigger:
    include:   
      - artifact: domains-*.yml # Not implement 
        job: build
##
# domains.yml
domain1-build:
  stage: build
  artifacts:
    paths:
      - domain1.yml
domain1:
  stage: trigger
  trigger:
    include:
      - artifact: domain1.yml # create the domain1.yml with deploy, test...
        job: domain1-build
domain2-build:
...
domain2:
...
domain3-build:
...
domain3:
...
#

What do you think? Is there a problem increasing this value by 1? I thought I saw in a issue that the initial idea was to set this value to 5, I find that 3 is a good compromise O:-)