Navalis - Larva without Queen/Hivecore can unburrow into the water

[MistChristmas]

Testmerges

N/A

Round ID

N/A

Description of the bug

Title.
Probably more a code fix than a mapping one. But I didn't look that hard.

What's the difference with what should have happened?

They should unburrow onto the weeds on that z level, not the water.

How do we reproduce this bug?

1. Late join as burrowed larva without a Queen or Core around
2. Go swimming

...

Issue Bingo

• Issue could be reproduced at least once
• Issue happened in a recent (less than 7 days ago) round
• Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)

[MistChristmas]

#8387 / #12166 Exclusive ... for now