Audit Instance Level CI Variable changes

What does this MR do and why?

Fixes Add missing instance-level variable changes to ... (#435713) • Sam Figueroa • 17.2 • At risk

Previously changes to instance variables were not correctly audited due to differences in services used to projects and groups.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Before	After
You stare into the void

How to set up and validate locally

1. Login as instance admin
2. Add/change CI variable on instance level
3. Go to instance level audit events
4. Profit