RADIUS no longer works after upgrading php version to 8.1

[cldx81]

@dapphp we were using PHP 7.4 for a while, recently migrated the entire application to PHP 8.1, everything works except RADIUS.

I suspect this has something to do with some of the deprecation and new requirements from PHP 8.0+ (e.g. certain functions such as strlen(), count(), trim() etc.. will no longer accept null values and so forth.)

We are basically dead in the water right now with our PHP version upgrade process, could be really cool if dapphp/radius be adapted to be compatible with PHP 8.0+, there is already a pull request in this regards, maybe it can be useful.