Investigate usage of toggleContainerClass in epic utils
https://gitlab.com/gitlab-org/gitlab/-/blob/f47a4b87234a6206e5e28e6a13373ae7d578955e/ee/app/assets/javascripts/epic/utils/epic_utils.js#L21-27 seems to be unused. We probably can remove it, given that the righthand sidebar works in Epics:
Edited by Lukas 'ai-pi' Eipert