Replace usage of @functools.lru_cache(max_size=None) with @functools.cache once python 3.8 is dropped

[parthea]

Once Python 3.8 is dropped, we should use @functools.cache, which was added in Python3.9, instead of @functools.lru_cache(max_size=None)

From https://docs.python.org/3/library/functools.html#functools.cache,

@functools.cache returns the same as lru_cache(maxsize=None), creating a thin wrapper around a dictionary lookup for the function arguments. Because it never needs to evict old values, this is smaller and faster than lru_cache() with a size limit.