Move calculation logic out of EE

Original Intent:

Should this code be in EE? Or should it remain in CE?

N/A Won't do - Code belongs in EE

This means the code stays in EE. gitlab.com is the only customer for this feature, and gitlab.com has an Ultimate license. The calculation should apply to every pipeline that runs on gitlab.com, regardless of the plan tier that the SaaS customer has paid (or not paid) for

Reasoning via @drew