Merge branch 'rc/followup-40690' into 'master'

Remove db/fixtures/test/01_admin.rb (EE backport)

See merge request gitlab-org/gitlab-ce!15711

db/fixtures/test/01_admin.rb

-require './spec/support/sidekiq'
-
-Gitlab::Seeder.quiet do
-  User.seed do |s|
-    s.id = 1
-    s.name = 'Administrator'
-    s.email = 'admin@example.com'
-    s.notification_email = 'admin@example.com'
-    s.username = 'root'
-    s.password = '5iveL!fe'
-    s.admin = true
-    s.projects_limit = 100
-    s.confirmed_at = DateTime.now
-  end
-end