Decrease ABC threshold to 55.24

What does this MR do?

• Refactor lib/github/import.rb:167:5 with extracting method
• Decrease ABC threshold to 55.24

Are there points in the code the reviewer needs to double check?

• ⚠ We can decrease threshold to 55.24 only after merging !13778 (merged) (or another one, decreasing ABC for app/controllers/autocomplete_controller.rb:6:3) ⚠

Why was this MR needed?

It's fourth step for #28202 (moved)

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

#28202 (moved)

/cc @rymai @markglenfletcher @grzesiek @rspeicher @blackst0ne

Possible labels: Community Contribution backstage Edge static analysis