Move VersionCheck to cron job

.rubocop_todo/gitlab/bounded_contexts.yml

.rubocop_todo/gitlab/namespaced_class.yml

.rubocop_todo/lint/unused_block_argument.yml

.rubocop_todo/rspec/context_wording.yml

.rubocop_todo/rspec/feature_category.yml

app/controllers/admin/version_check_controller.rb

app/helpers/version_check_helper.rb

app/workers/all_queues.yml

app/workers/gitlab/version/version_check_cron_worker.rb

config/initializers/1_settings.rb

ee/spec/features/admin/admin_dashboard_spec.rb

lib/version_check.rb

spec/features/admin/dashboard_spec.rb

spec/features/help_dropdown_spec.rb

spec/helpers/version_check_helper_spec.rb

spec/lib/version_check_spec.rb

spec/requests/admin/version_check_controller_spec.rb

spec/spec_helper.rb

spec/support/helpers/version_check_helpers.rb

spec/support/rspec_order_todo.yml