Limit cache size for ArrayCache

[clue]

The ArrayCache keeps growing and growing when new data is added to it. We should probably add an optional parameter to limit the cache size and implement a simple LRU algorithm to remove "old" entries.

[WyriHaximus]

When would we run the algorithm to clean up? Maybe we could go with FIFO instead which could be simpler. ArrayCache should be replaced with another implementation in larger apps honestly: https://github.com/reactphp/react/wiki/Users#cache-implementations (we could use more tbh)

[clue]

When would we run the algorithm to clean up? Maybe we could go with FIFO instead which could be simpler.

"LRU algorithm" may sound more complicated than it actually is :-) This essentially means you keep track of the entries that were last accessed and simply remove the oldest one once adding a new entry to the cache.

ArrayCache should be replaced with another implementation in larger apps honestly: https://github.com/reactphp/react/wiki/Users#cache-implementations (we could use more tbh)

No objections, I think this mostly boils down to good documentation though 👍 I think having ArrayCache as a default makes sense for most use cases, but we should probably prominently suggest using alternative implementations for the more specialized use cases 👍