Add new job only for lintian package to ensure the Apertis profile is not broken

This MR adds two jobs only triggered when the lintian package is built to ensure the Apertis profile is working.

• The first job lintian-errors triggers the build pipeline of the fake package tests/lintian-errors. The aim of this fake package is to trigger lintian tags only with the Debian profile but not with the Apertis profile.
• The second job lintian-errors-test, retrieves the newly built lintian on OBS and then uses it to check the pkg lintian-errors.

Currently, it is possible to test it with pkg/lintian!13 (merged)

https://phabricator.apertis.org/T8873

Signed-off-by: Dylan Aïssi dylan.aissi@collabora.com