Nightly built artifacts for disabled jobs are not removed

Originally created by @intrigeri on #8912 (Redmine)

Once we build all active branches, we’ll have lots of stuff on nightly.t.b.o for branches that we don’t build anymore. We can’t allow this to grow endlessly, so artifacts need to be removed once the corresponding branch isn’t built automatically anymore.

Feature Branch: feature/8912-automatic_disabled_jobs_artifacts_deletion

Parent Task: #6196 (closed)

Related issues

• Related to #7107 (closed)
• Related to #9350 (closed)
• Related to #9616 (closed)
• Related to #10123 (closed)
• Blocks #8658 (closed)