Grape API runs lots of SQL queries every 5 minutes on GitLab.com

As per the following screenshot it seems something (most likely CI) is triggering some Grape API every 5 minutes that ends up running a lot of SQL queries:

Steps to take here are:

1. Find out which APIs CI uses
2. Find out which API(s) is/are triggering these SQL queries
3. Create a separate issue for every API describing the behaviour, problems, etc