Floating water above tall grass

Summary:

When water sources are placed by world generation above tall grass, it doesn't destroy the tall grass.

To reproduce:

1. Generate a Creative mode world in 21w37a with default world settings and the seed `-7206245882723273550`.
2. `/gamemode spectator`
3. `/tp @s 214 31 -331 90 0`
4. Look.

Screenshot: