Top-level group admins get puzzling emails about buying more CI minutes.
This is an automated notification to let you know that your CI Runner Minutes quota for "Information Services" is below 5%.
Click here to purchase more minutes.
If you need assistance, please contact GitLab support.
This is a benign UI bug introduced in the 12.1.0 release of GitLab. There is a blog post from GitLab explaining the bug.
You can track the progress of its resolution in the upstream issue on GitLab.com.
Affected users may disregard the emails.