You can use unclosed menus from different z-levels to vend items.

### Testmerges

#9894, #10340, #10830, #9141, #10895, #8846, #10872, #10883, #10908

### Round ID

30476

### Description of the bug

If you do not close menus, say from things like the Req vendors, you can walk where they would be on another Z-Level and use them freely.

### What's the difference with what should have happened?

You should not be able to reach into vendors from different z-levels to vend items straight through the floor.

### How do we reproduce this bug?

https://github.com/user-attachments/assets/b882bd14-2bdb-472d-9b8b-affed3ad7950

### Issue Bingo

- [x] Issue could be reproduced at least once
- [x] Issue happened in a recent (less than 7 days ago) round
- [x] Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)