Fix version_interval_spec.rb tests

What does this MR do?

This merge request addresses issues with the version_interval_spec.rb tests in the codebase, where the tests were not properly written and failed to correctly test the intended functionality. These corrections make the tests meaningful and capable of verifying the intended functionality of the version interval handling logic, preventing us from introducing regressions without realizing.

What are the relevant issue numbers?

Audit semver_dialects tests (gitlab-org/gitlab#439114 - closed) • Philip Cunningham • 16.10

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for this project, if necessary
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Security reports checked/validated by reviewer