Road gen artifacts

### Describe the bug

Sometimes road generates a lot of 4 tiles deep dead ends. Screenshots are of vertical type, but I've seen horizontal too

### Attach save file

[t-roads-trimmed.tar.gz](https://github.com/CleverRaven/Cataclysm-DDA/files/13843074/t-roads-trimmed.tar.gz)

### Steps to reproduce

1. make a new word
2. long range teleport and map reveal / wander until you stumble upon a row of very short T intersections

### Expected behavior

To roads to mostly make sense

### Screenshots

Overmap:

Main view:

### Versions and configuration

- OS: Windows
- OS Version: 10.0.19045.3803 (22H2)
- Game Version: ee14785 [64-bit]
- Graphics Version: Tiles
- Game Language: English [en]
- Mods loaded: [
Dark Days Ahead [dda]
]

### Additional context

_No response_

Load the attached t-roads-trimmed.tar.gz save file and follow the reproduction steps by revealing or exploring the overmap until the short T-intersection row appears. Then locate the road-generation entry point and compare generated layouts with the screenshots; done means preventing repeated four-tile-deep dead ends while preserving sensible road connections.

Written by the indexing model from the issue text.