Resolve "Protected branch dropdowns cut-off in Repository Settings page"

What does this MR do?

Fixes repository settings panel dropdown cutoff issue.

To fix this, we overflow: visible each expanded section element in order to allow the dropdowns to overflow the section. Note this can only be done on animationend or the sections content will be visible during transition.

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

Why was this MR needed?

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
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #33693 (closed)