Bug: Web Edit makes changes against the fork default branch, not the fork origin default branch

1. go to https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/views/notify/merged_merge_request_email.html.haml
2. choose edit this file only from edit dropdown
3. you will be redirected to https://gitlab.com/gitlab-org/gitlab/-/update/master/app/views/notify/merged_merge_request_email.html.haml
4. do changes, fill nice commit message, press save
5. continues to display Someone edited the file the same time you did. Please check out the file and make sure your changes will not unintentionally remove theirs.
6. check that last commit to the file was year ago (6d78fbf0)
7. retry 2-4, this time being annoyed that your changes were lost
8. retry several times, realize you will not win
9. create this bug report

PS: change I wanted to make was:

%p
  Merge request #{merge_request_reference_link(@merge_request)} was merged to {@merge_request.target_branch} branch

git commit -m "Add target branch to merged merge request notify email"