Please add support for PHP 8

[falxen]

When installing this using composer, one needs to use --ignore-platform-reqs for every future action on composer e.g. update or to install any other package because of this error:

Problem 1
- averias/phpredis-json is locked to version 1.4.0 and an update of this package was not requested.
- averias/phpredis-json 1.4.0 requires ext-redis ^5.0.1 -> it has the wrong version installed (6.0.0-dev).
- averias/phpredis-json 1.4.0 requires php ^7.2 -> your php version (8.1.6) does not satisfy that requirement.