Resolve "BS4: Pagination is pipeline's page has no styling"

What does this MR do?

Adds the styling back to the pagination on the pipelines page.

Are there points in the code the reviewer needs to double check?

I'm pretty sure there aren't any side effects to other pages, but I'm not 100% sure where all the pagination elements are used. It may be beneficial for someone with better knowledge of the app and codebase to take a second look.

Why was this MR needed?

Because the bootstrap 4 upgrade removed the styling.

Screenshots (if relevant)

With 2 pages

With 100+ pages

Concatenated for smaller screens

Page 2 on smaller screens

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #46878 (closed)