Alter Flaky.ok? behaviour

[luke-hill]

Description

Change the result of Flaky.ok? to true always.

Type of change

• Refactoring (improvements to code design or tooling that don't change behaviour)
• Breaking change (will cause existing functionality to not
  work as expected)

Please add an entry to the relevant section of CHANGELOG.md as part of this pull request.

Note to other contributors

I've refactored a bunch of test code to be individualistic and in the individual files alongside this PR to help review changes

Checklist:

Your PR is ready for review once the following checklist is
complete. You can also add some checks if you want to.

• Tests have been added for any changes to behaviour of the code
• New and existing tests are passing locally and on CI
• bundle exec rubocop reports no offenses
• CHANGELOG.md has been updated