* Fix PHP 8.4 deprecation
Implicitly marking parameter as nullable is deprecated, the explicit nullable type must be used instead
* [github workflow] Add additional php versions
libcurl-impersonate was not being used properly, as the code was
overriding the headers set by it to prevent detection.
- update the libcurl-impersonate to an actively managed lexiforest
fork
- impersonate Chrome 131
- move the defaultHttpHeaders to http.php, where it belongs
- only set defaultHttpHeaders if curl-impersonate is not detected
- make useragent ini setting optional and disabled by default
- add necessary documentation updates
