vim: Fix % not working for multi-char bracket pairs (#23471)

Closes #23358

Demo/proof:


https://github.com/user-attachments/assets/2036d183-8830-415b-9155-0d3efe3d824c




Release Notes:

- Fixed `%` in Vim mode not working correctly for multi-char brackets,
such as `do/end` in Elixir or `\begin` and `\end` in LaTeX.

Co-authored-by: Conrad <conrad@zed.dev>