Temporarily disable the old CI configuration file and replace it with
the one belonging to the reworked CI infrastructure.

The project CI/CD settings should be updated in order to switch
'CI/CD configuration file' from 'ci/.gitlab-ci.yml' to the default
'.gitlab-ci.yml', for consistency with Mesa CI.

Note the 'ci/' folder becomes obsolete in favor of '.gitlab-ci/' and
could be removed once all needed functionality has been migrated to the
new setup.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Rohan Garg <rohan.garg@intel.com>