Bug report

type in the out parameter of parse_str doesn't support nested arrays and doesn't represent the real value used by the function.

Code snippet that reproduces the problem

<?php
parse_str('filter[x][y]=0', $output);
print $output['filter']['x']['y'];

https://phpstan.org/r/6f758dd6-6fff-4bb7-b80c-c74946f01e74

Expected output

The issue is reported incorrectly since PHP 8.1 executes this code without errors.