Update _form.html.haml (deploy tokens) to improve display of scopes

What does this MR do?

A slight touchup to the view in Deploy Token Scopes, Settings->Repository->Deploy Tokens, so that it matches the view of the Personal Access Token Scopes.

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

Make sure it actually displays properly, I can't test it myself. I'm hoping that it'll look like Personal Access Token Scopes:

Scopes

• read_repository
  Allows read-only access to the repository
• read_registry
  Allows read-only access to the registry images

Screenshots (if relevant)

Currently looks like this:

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
• Conform by the database 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?