### Context This issue is part of https://gitlab.com/groups/gitlab-org/-/epics/15666+ see that epic for more context. In https://gitlab.com/gitlab-org/gitlab/-/issues/500610+ we implemented the ability for an instance admin to allow list integrations. ### Proposal When an instance has configured their integrations allow list, a notice should display to instance, group and project admins when they visit the integrations settings index that the allow list is active, so they understand why some integrations are not available. ### Technical proposal We could make the [`Integration.instance_allows_all_integrations?`](https://gitlab.com/gitlab-org/gitlab/-/blob/6010a33d68859beb94e2752e1d1fa1f1dc5cc070/ee/app/models/concerns/ee/integrations/base/integration.rb#L103-105) method public to use it in the check for this feature. If the instance does not allow all integrations the ~frontend would display an alert notice on the integration settings index page at instance, group and project-levels.