While exploring the `vim` crate, I found that `ShellCommand` is
registered twice with identical closure bodies in
`crates/vim/src/command.rs`
[L331-L357](https://github.com/zed-industries/zed/blob/main/crates/vim/src/command.rs#L331-L357)
. This PR removes the redundant code block to clean up.

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- N/A

Co-authored-by: dino <dinojoaocosta@gmail.com>