Integrate gitlab-ci/CI-readd-allow-failure-true

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Commit: seco-ne/yocto/infrastructure/gitlab-ci@ea3aa816

CI: Readd allow_failure:true to fix not finished pipelines

According to the docs a manual job always has allow_failure set to
true, but we see a lot of jobs staying in an unfinished state since
the removal of the allow_failure: true keyword for the sdk and test
jobs. This should fix the broken behaviour.