Merge branch '397073-epic-relations-non-members-subepics-controller' into 'master'

Update controller permissions to set parent of an epic

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135427



Merged-by: Florie Guibert <fguibert@gitlab.com>
Approved-by: Joseph Wambua <jjoshua@gitlab.com>
Approved-by: Rajan Mistry <rmistry@gitlab.com>
Approved-by: Nicolas Dular <ndular@gitlab.com>
Reviewed-by: Nicolas Dular <ndular@gitlab.com>
Co-authored-by: Eugenia Grieff <egrieff@gitlab.com>