Fix RSpec/BeEq issue in spec/presenters/blobs/unfold_presenter_spec.rb

This issue is part of the Source Code Management backend team's effort to resolve RuboCop violations.

Violation

File: spec/presenters/blobs/unfold_presenter_spec.rb Cop: RSpec/BeEq

Steps to resolve

1. Remove the entry from the RuboCop todo file
2. Fix the violation in the code
3. Ensure tests pass
4. Submit the merge request