"Look up" allows marines to see through xeno forts/walls when near caves

## Testmerges
#9427: 'external authentication system' by hry-gh at commit dd1dfe45c1
#9590: 'Multi Z Almayer [MDB IGNORE]' by spartanbobby at commit 52af8cb863
#9894: 'Multiz indicator' by Detective-Google at commit f292a2718b
#9175: 'Multiz climbing changes' by cuberound at commit 361353d63c
#9978: 'Xeno Time Checks' by realforest2001 at commit f2cb166488
#9893: 'Scout now has a built in radio telephone in its helmet' by Red-byte3D at commit 4a930aee49
#9872: ' Multiz Bigred [MDB IGNORE]' by spartanbobby at commit 40c5cef882
#10051: 'fucking fix look up' by jupyterkat at commit 920066fc95

## Round ID
29076

## Description of the bug
If there is a ledge above a cave entrance, and you "look up" you can see what is on the other side of xeno resin walls.

## What's the difference with what should have happened?
Instead, when you use "look up" near the cave you should not be able to see through xeno resin walls. Try this on Solaris Ridge

## How do we reproduce this bug?
1. go near cave entrance with a ledge near it, and stand on the regular z level
2. place xeno resin walls on the ground, which marines cant see past while on the first z level
3. marine can see through xeno walls when pressing "look up"

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

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