Remove pipeline editor feature flag [RUN ALL RSPEC] [RUN AS-IF-FOSS]
What does this MR do?
The Pipeline Editor is no longer behind a feature flag, we remove all related code including tests.
Due to a recent change, removing a feature flag, even one that was defaulted to true, require a changelog so I've added one
Screenshots (strongly suggested)
No visual changes. Here is a screenshot of the Editor link in navigation and the section, still working.
Does this MR meet the acceptance criteria?
Conformity
Availability and Testing
We are removing tests for the use cases that were testing the feature flag being disabled.
Edited by Frédéric Caplette