Cluster and Pylon can be placed on the same tile

## Testmerges
#6334: 'Xenomorph Endgame' by Git-Nivrak at commit e561484aac
#6400: 'Adds Sunsets to Roundstart, adds Sunrises to Marine Victories, and Survs can hear Evo Announcement Screeches now' by GrrrKitten at commit 2927345720
#6308: 'Hostile Survivor Rework' by Steelpoint at commit bf51f9e551
#6248: 'New Map: LV-759 Hybrisa Prospera' by Zenith00000 at commit 0df80601dd
#6633: 'Light Emote Refactor and Heavy Emote Expansion' by GrrrKitten at commit fe7a420eb0
#6568: 'Chemical simulator TGUI' by kiVts at commit 159437cfb1

## Round ID
23007

## Description of the bug
Pretty much what the title says. At the comms unit, you can (somehow) build a cluster and a pylon on the same tile.

## What's the difference with what should have happened?
Don't think they should be on the same spot.

## How do we reproduce this bug?
I do not know. I've only seen an incomplete cluster blueprint on top of a completed pylon. Upon completing the cluster blueprint, you get both pylon and cluster on the same time.

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

## Additional details
- Author: XQ
- Admin: Steelpoint
- Note: None