openttd: Update to 14.0

**Summary**

Highlighted changes:
- Improved ship pathfinder
- New unbunching feature
- (Optional) social platform integration
- Survey support
- GUI improvements and scalable font
- Improved new player experience

Full release notes available [here](https://www.openttd.org/news/2024/04/13/openttd-14-0)

Signed-off-by: Thomas Staudinger <Staudi.Kaos@gmail.com>