Reorganize emba control files

Reorganize emba control files

Using dynamic job generation in GitLab does not work sufficiently.  So
we generate the jobs in the Emacs sources.

* configure.ac (SUBDIR_MAKEFILES): Add test/infra/Makefile.

* test/Makefile.in (subdirs, generate-test-jobs): New targets.

* test/infra/Makefile.in:
* test/infra/test-jobs.yml: New files.

* test/infra/default-gitlab-ci.yml:
* test/infra/test-jobs-generator.sh: Remove.

* test/infra/gitlab-ci.yml: Insert contents of default-gitlab-ci.yml.
(stages): Remove generator and trigger.  Add normal.
(test-jobs-generator, test-jobs-pipeline): Remove jobs.
(top): Include test-jobs.yml.