Description

Currently, PHP will automatically convert some int-like strings to int when used as array keys.

1. this can lead to unexpected behavior, depending on the array keys used (since some will get typecast, while others won't, even though both would pass is_numeric())

2. this adds overhead for type juggling on all array operations, since values need to be type juggled

This has been discussed in #9029

I think it would make sense to create an RFC to stop doing this with PHP 8.5 (I don't have permission, otherwise I would have done that already)

Since most people are unaware that this happens in the first place, the impact would probably not be too big, but it is definitely a breaking change.