Autobuild ISOs cleanup loses all history for topic branches post-release

Originally created by @intrigeri on #10123 (Redmine)

The way we currently clean up autobuilt ISOs deletes all topic branches’ artifacts and Jenkins job history after each release, presumably because they’re not considered to be “active” anymore, and thus their Jenkins job is deleted, and in turn the corresponding artifacts are deleted (#8912 (closed)). That’s problematic because it makes it harder to track down regressions in a given topic branch, that would have been introduced by updates elsewhere in our source code. If we see the same behavior the Jenkins history of test suite jobs in the future, we may also lose valuable data there.

Feature Branch: pythonlib:bugfix/10123-dont-lose-all-history-for-topic-branches-post-release

Related issues

• Related to #8912 (closed)