Fix issues with lintian jobs

Two issues have be found when using lintian jobs on previous Apertis releases:

• lintian-errors-test job fails to retrieve the lintian-errors pkg from OBS when running for previous Apertis releases. lintian-errors is always built on the latest Apertis release, the path needs to be adjusted by using CI_DEFAULT_BRANCH variable.
• Apertis v2021 uses an old lintian version with an argument that has been renamed in newer versions, so we need to check the lintian version we are using to adjust the argument name.

https://phabricator.apertis.org/T8873

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