Remove admin mode entry

data/whats_new/202103220001_13_10.yml

-- title: "Admin Mode: Re-authenticate for GitLab administration"
-  body: |
-    GitLab now includes Admin Mode, which helps admins work safely from one account. When Admin Mode is not active, admins have the same privileges as a regular user. Before running administrative commands, admin users must reverify their credentials. Admin mode increases instance security by protecting sensitive operations and data. 
-  stage: Manage
-  self-managed: true
-  gitlab-com: false
-  packages: [Free, Premium, Ultimate]
-  url:  https://docs.gitlab.com/ee/user/admin_area/settings/sign_in_restrictions.html#admin-mode
-  image_url:  https://about.gitlab.com/images/13_10/manage_reauth_admin.png
-  published_at: 2021-03-22
-  release: 13.10
 - title: "GitLab Runner for Red Hat OpenShift GA"
   body: |
     The GitLab Runner Operator is generally available in the [Red Hat OpenShift Container Platform](https://www.openshift.com/products/container-platform). To install GitLab Runner on OpenShift, you can use the [GitLab Runner Operator](https://gitlab.com/gitlab-org/gl-openshift/gitlab-runner-operator), which is available from the stable channel in the OperatorHub. The Container Platform is a web console for OpenShift cluster administrators to discover and select Operators to install on their cluster. We are also developing an [Operator](https://gitlab.com/groups/gitlab-org/-/epics/3444) for GitLab, so stay tuned to future release posts for those announcements.