Add support for PHP 8.2, 8.3 and 8.4

[marclaporte]

https://github.com/steverhoades/oauth2-openid-connect-client/blob/master/README.md indicates support for PHP 8.1

https://www.php.net/supported-versions.php indicates that for PHP 8.1, active support ended about 1 year ago (25 Nov 2023) and security support will end in about one year (31 Dec 2025)

This MR indicates it adds support for PHP8.3:
#42