This only changes behaviour for masters, as developers are already prevented from updating/deleting tags without the Protected Tags feature

Fixes ProtectedBranches#create flash errors bug due to
typo in 'flash[:alert] = @protected_branches.errors'

This memorized array appears to originally come from https://gitlab.com/gitlab-org/gitlab-ee/commit/19c2c90ccac86a21eb4266b9a5972162f917f692 which has a commit message of ‘fix warnings’. Without any comments on the original pull request I think we can safely get rid of it unless warnings re-appear.

Makes it clear this is only used in dropdowns, instead of cluttering up Project class. Since we only care about branch names, it is also possible to refactor out a lot of the set/reject logic.

A benchmark on Array/Set subtraction favoured using Arrays. This was with 5000 ‘branches’ and 2000 ‘protections’ to ensure a similar comparison to the commit which introduced using Set for intersection.

Comparison:
   array subtraction:      485.8 i/s
     set subtraction:      128.7 i/s - 3.78x slower

Uncommented protected tags feature specs copied from protected branches

Fixed timestamps on protected_tags

Should provide basic CRUD backend for frontend to work from. Doesn’t include frontend, API, or the internal API used from gitlab-shell

Added schema.rb for protected tags

Fix Error 500 when application settings are saved

Closes #29674 and #29115

See merge request !10070

Add filter focus for filtered search visual tokens

See merge request !9875

add an index to the ghost column

See merge request !9910

Make the v3_to_v4.md more consistent

See merge request !10092