Fix error loading javascript in edit tags form

What does this MR do?

Fix error loading javascript in edit tags form. This error only takes place in 10.5 and is fixed on master because of a different refactor. I've created a MR that targets 10-5-stable.

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

None

Why was this MR needed?

Fix regression

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/43803