gitlab-ci: Use my own set of jobs for CI pipeline

This is an example to use a different set of jobs than the
mainstream one (currently 116 jobs).

Here I only select 2 jobs:
- cross-s390x-kvm-only
- build-libvhost-user

Including their dependencies, I have to run 8 jobs.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
8 jobs for gitlab_in_forks in 15 minutes and 25 seconds (queued for 2 seconds)
Child pipeline (parent) latest
Status Name Job ID Coverage
  Containers
passed amd64-centos8-container #1168609696

00:02:40

passed amd64-debian10-container #1168609698

00:02:42

passed amd64-fedora-container #1168609697

00:03:51

 
  Containers Layer2
passed s390x-debian-cross-container #1168609699

00:02:54

 
  Build
passed build-libvhost-user #1168609702

00:03:06

passed check-dco #1168609701

00:01:06

passed check-patch #1168609700

00:01:06

passed cross-s390x-kvm-only #1168609703

00:09:37