Enable New project runners UI

What does this MR do and why?

Enable New project runners UI

This MR enables the new UI project runners UI. This UI uses a tab navigation to display the runner assigned to a project, as well as runner available for use in a project.

It removed the vue_project_runners_settings as-if enabled, so all users see the new UI.

Changelog: changed

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Visit the CI/CD settings in your project
   • e.g. https://gdk.test:3000/my-group/my-project/-/settings/ci_cd
2. Expand the Runners section
3. Check the New UI runner UI (with tabs to see types of runners) is visible.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #527130