Backport v2022<-v2023dev3: Use 2021 as well known release
Backport !100 (merged)
Since packages for Apertis 18 are not longer available switch to Apertis 2021 as well know release to run tests.
Initially some tests were done to use 2019 or 2021, however, some issues, such as test failures, were found. Since 2019 and 2020 are not longer supported there is no point in investigating/fixing the issues, so better move to v2021 which is the currently supported oldest release.
Signed-off-by: Walter Lozano walter.lozano@collabora.com