Merge branch 'feature/jramsay/remove-fork-relationship' into 'master'

Remove fork relationship

See merge request gitlab-com/www-gitlab-com!34530

data/release_posts/unreleased/jramsay-remove-fork-relationship.yml

+features:
+  secondary:
+    - name: "Remove fork relationship when project visibility is restricted"
+      available_in: [core, starter, premium, ultimate]
+      documentation_link: "https://docs.gitlab.com/ee/public_access/public_access.html#reducing-visibility"
+      reporter: jramsay
+      stage: create
+      issue_url: "https://gitlab.com/gitlab-org/gitlab/issues/33358"
+      description: |
+        Forking workflows makes it easy to contribute to any project by
+        creating a copy of the upstream project to work on before opening a
+        merge request to merge your changes into the upstream project.
+        Previously, when the visibility of the root project in a fork network
+        was restricted, the visibility of all the forks would be restricted.
+        This could result in all forks of a public project suddenly becoming
+        private if the root project was made private.
+
+        In GitLab 12.6, instead of changing the visibility of all projects,
+        the root project is simply removed from the fork network leaving all
+        other projects unmodified. This is equivalent to the root project being
+        deleted.