Update //flora for 1.21.5 Spring Drop

### The Problem

Spring Drop (1.21.5) added many new ambient natural grasses and bushes to worldgen which is really cool, and I would love to keep //flora up to date by adding said blocks to its generation.

### A Solution

Add the new blocks to //flora generation and checks depending on biome type

Such as firefly bushes, bush (the block), dry grass, etc

### Alternatives

_No response_

### Anything Else?

_No response_