Update index.rst

[luizcmarin]

With "php composer.phar require "cakephp/authentication:^2.0"" result...

"Your requirements could not be resolved to an installable set of packages.

Problem 1

• zendframework/zend-diactoros[2.0.0, ..., 2.2.1] require php ^7.1 -> your php version (8.2.3) does not satisfy that requirement.
• cakephp/authentication 2.0.0 requires zendframework/zend-diactoros ^2.0 -> satisfiable by zendframework/zend-diactoros[2.0.0, ..., 2.2.1]. - Root composer.json requires cakephp/authentication 2.0 -> satisfiable by cakephp/authentication[2.0.0]."

BUT, with the change continues the installation without problems. (*Cakephp 4.4.11, windows 10, php 8.2.3)