Cache_once density function doesn't work

Steps to Reproduce:

Create a new world with the attached world generation datapack and explore new chunks.

Observed Results:

Chunk generation performance is terrible. Performance gets worse at an exponential rate as further x_n and y_n density functions are added to the datapack (following the pattern of x1-x12 and y1-y12).

Expected Results:

Chunk generation performance should be acceptable. Performance should get worse at a linear rate as further x_n and y_n density functions are added.

Notes:

The attached datapack is useless in practice, it's only purpose is to highlight a performance issue. The x_n and y_n density functions perform a pointless iterative calculation on the x and y noises. The result of this iteration is then referenced by the erosion density function just so that the iterative calculation is actually performed. With proper cahcing, the entire thing is a series of 20-something additions and multiplications, which doesn't justify the low performance.

I've encountered this issue while working on actual world generation datapacks, and found it to be the single biggest limitation when trying to generate complex terrain. I believe this also affects vanilla world generation performance to a limited extent.