CI: rename ci-feature::test-rolling-upgrade into ci-feature::test-rolling-update

@loic.nicolle, we renamed ci-featuretest-rolling-upgrade into ci-featuremgmt-rolling-update but our code was still using the old one (and hence, to keep using the feature, people must have added back the old ci-featuretest-rolling-upgrade label).

This MR changes the code so that we can reach something clean.

Related to !2844 (merged) discussion