Reinstate RSpec/TimecopFreeze offenses

What does this MR do and why?

!76030 (merged) removed some RSpec/TimecopFreeze offenses from .rubocop_todo/rspec/timecop_freeze.yml which were still offenses, and caused the rubocop job to fail.

This reinstates the offenses after running:

bundle exec rake rubocop:todo:generate

#347188 (closed)

How to set up and validate locally

 bundle exec rubocop --only 'RSpec/TimecopFreeze' .

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #347188 (closed)