Separate default branches for MRs and for tags
### Problem to solve
We use a git flow-like workflow, with two permanent branches, master and dev. Feature branches (which are ~90% of branches) get merged into dev, and to facilitate that we have our default branch set to dev. When we have a hotfix, the MR goes into master, and we then tag master with a patch release and trigger a CI build/deploy to prod. Because the New Tag page ( /namespace/projects/tags/new ) defaults to using the default branch, on several occasions we've accidentally tagged dev with the patch release instead of master.
### Further details
(Include use cases, benefits, and/or goals)
### Proposal
In the simplest implementation, the repository settings page would allow you to specify multiple default branches - one for MRs, and one for tags.
### What does success look like, and how can we measure that?
(If no way to measure success, link to an issue that will implement a way to measure this)
### Links / references
* In a twitter thread, Gitlab brought up https://gitlab.com/gitlab-org/gitlab-ee/issues/7211 as another example of something that is difficult because of the conflation of HEAD and default branch.
issue