Star Shells get stuck in the upper zlevel

## Testmerges
#9427: 'external authentication system' by hry-gh at commit 00232abe2d
#9493: 'The Overthrall & Blooded Thralls' by MeH0y at commit 2cb1fc47de
#9590: 'Multi Z Almayer [MDB IGNORE]' by spartanbobby at commit 504ce34962
#9872: ' Multiz Bigred [MDB IGNORE]' by spartanbobby at commit 4ec278536d
#9175: 'Multiz climbing changes' by cuberound at commit b27bb7ff15
#8878: 'Whiskey Outpost Xenofication' by Unknownity at commit cf7272d66b
#9193: 'Trijent Z levels' by BOBAMAx at commit a444e49822
#9894: 'Multiz indicator' by Detective-Google at commit d88517e19b
#9421: 'Tgui rspack fixes and misc tgui fixes' by Drulikar at commit 481e9947f3
#9853: 'More channel lowertext' by Drulikar at commit c2622996f1

## Round ID
28719

## Description of the bug
If you shoot a Star Shell at the upper z-level tile near open space, shells don`t fall down z-level and get stuck in the "air".

## What's the difference with what should have happened?
Star shell should fall to the lower z-level.

## How do we reproduce this bug?
1)Shoot a grenade launcher loaded with M74 AGM-S Star Shell at upper z-level tile near open space
2)Observe

## Attached logs
```
N/A
```

## Additional details
- Author: Labeo0
- Admin: X31stOverlord
- Note: None