E2E: Use UI to create top-level group

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/129906



Merged-by: Sanad Liaquat <sliaquat@gitlab.com>
Approved-by: Harsha Muralidhar <hmuralidhar@gitlab.com>
Approved-by: Ramya Authappan <rauthappan@gitlab.com>