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>
2 jobs for gitlab_in_forks in 1 minute and 57 seconds (queued for 2 seconds)
latest
Status Name Job ID Coverage
  Build
passed generate-config #1168607634

00:01:57

 
  Test
passed generate-pipeline