Wheelchairs can't traverse Multi-Z staircases

## Testmerges
#10830: 'CMLIVE!™️' by hry-gh at commit c04903d407
#10883: 'Blocks tiles you cannot view while looking up' by Git-Nivrak at commit 5d0d58b9f6
#10926: 'Medals Overhaul' by realforest2001 at commit 7df4ad80f9
#10999: 'Fix of various plane related issues' by Blundir at commit f85a7153c4
#11024: 'Announcement garble w/o coms and stars_decode_html fix' by Drulikar at commit 922b12594f
#10376: 'CIA Overhaul' by realforest2001 at commit 18a0bfd501
#9575: 'Oppressor Praetorian: Fixes abduction ability interaction with objects.' by Venuska1117 at commit ff7f8a7550
#11123: 'Temp Alt Research Remap' by realforest2001 at commit c2acaa7c5a
#10965: 'Leadership Changes: Focus Mode Buffs' by Nihisohel at commit 44c12ca1dd
#10973: 'Leadership Changes: Fireteam Additions' by Nihisohel at commit 24ea130585

## Round ID
30927

## Description of the bug
When you're in a wheelchair, you're blocked from moving up Z-level via. the stairs.

## What's the difference with what should have happened?
I expected to be able to go between Z levels with a wheelchair, just as I would if I didn't have one.

## How do we reproduce this bug?
1) Be in a wheelchair
2) Try and move between Z-levels via Almayer stairs
3) Fail miserably

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

## Additional details
- Author: BasilHerb
- Admin: SmellyHippie
- Note: None