Replace ref_switcher partial in app/views/projects/tree/_tree_header.html.haml
We're in the process of migrating away all uses of Bootstrap. Whilst this is a simple task for things such as buttons and alerts, dropdowns are much more complex. Because of that, there will be no step-by-step instructions in this issue.
This dropdown can be migrated to our ref_selector Vue component, for more info see: &8528