Update to phpseclib v3

[nicolas-ristocloud]

As per title, phpseclib v3 is the recommended version of the library by the authors, with better compatibility for php 8.4 and also other libraries like league/flysystem.

[davideleonelli99]

I'm also interested in an update to phpseclib v3, as it would allow me to upgrade the library to version 1.4 in a Magento 2.4.7 project.
Thank you

[beppause-it]

tested fork for compatibility with phpseclib v3

"repositories" : [
{
"type": "vcs",
"url": "https://github.com/beppause-it/gbusiness-api-php-sdk.git"
}
],

"require" : {
    "satispay/gbusiness-api-php-sdk": "dev-master#aecf247"
}