reduce TTL cache maxsize

[Kilo59]

I believe the cache sizes can be much lower still.
AFIAK the maxsize isn't the "size" of the cache so much as it is the number of recent calls to the function to save. get_category() only has 3 possible parameters it receives. So my understanding is as long as the max size is greater than those 3 different function calls everything should work fine.

As per the standard lib lru cache which I believe cachetools is based on.

https://docs.python.org/3/library/functools.html#functools.lru_cache

Decorator to wrap a function with a memoizing callable that saves up to the maxsize most recent calls.

Future steps

• investigate and further optimize the cache settings to reduce memory usage