spent flares block eggs and cannot be melted

### Testmerges

#9894: 'Multiz indicator' by Detective-Google at commit 5dbc10a0d2 #9978: 'Xeno Time Checks' by realforest2001 at commit f86f8e3705 #8878: 'Whiskey Outpost Xenofication' by Unknownity at commit 702a29044e #10384: 'Fixes queen transparency issues and keybinds it' by Red-byte3D at commit 34d2c150e3 #7093: 'creates ipcheck subsystem' by hry-gh at commit 56b82d8df5 #9872: ' Multiz Bigred [MDB IGNORE]' by spartanbobby at commit bb10124ab1 #10432: 'Hud rework part 1 : Human action icons remake' by Blundir at commit dc5ca047b8 #10529: 'Revert "Allows Queen Eye to look into tents (#10494)"' by realforest2001 at commit a70e338b85 #10376: 'CIA Overhaul' by realforest2001 at commit 871c54b397

### Round ID

29735

### Description of the bug

spent flares (flares that are no longer providing any illumination) block egg placement and cannot be melted (when you try, the acid appears for a split second and then disappears)

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

either they shouldn't block eggs/traps, or they should be meltable, or both

### How do we reproduce this bug?

1. throw flare on ground
2. wait for it to not be lit anymore
3. try to plant an egg on the tile, or to melt the used-up flare

### 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)