Fixer to turn array_key_(first|last) into array_(first|last)

[chriscpty]

PHP8.5 added array_first and array_last functions.
Before this, we used $array[array_key_first($array)] as a quick way to get the first/last element of an array a lot. A fixer to replace this overcomplicated syntax with the way simpler array_first($array) would be cool.

The rule could probably also turn array_find(fn() => true) and similar "Using array_find to find the first element" calls into array_first too.

This would be a risky rule, as it does change the behavior slightly: The array_key_first logic would throw an error when using it with an empty array, while the array_first logic returns null instead.

I'd be willing to give implementing this a shot if i get the OK from a maintainer👍