You can create walls in the van

### Testmerges

-

### Round ID

31645

### Description of the bug

You can have secured girders (and by extension walls) in the van by dislodging it and moving it into the van while another person is securing it.

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

You shouldn't be able to construct walls in the van (putting girders inside as well).

### How do we reproduce this bug?

1. Build a wall girder and dislodge it
2. Person A should grab it and start moving it into the van
3. Person B should start securing the girder before it gets into the van
4. Now that you got a secured girder in the van, you can make regular or reinforced wall out of it

https://github.com/user-attachments/assets/b3303bf3-883d-4f19-80d5-01388380cb5f

### 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)