PHP 8.1 is available off the shelf in openSUSE Tumbleweed. I will shortly prepare a PHP 8.1 / tumbleweed version of the maintaina Horde containers. These will initially be broken due to some outdated language constructs. As PHP 7.4 will EOL by the end of this year, I decided not to bother with PHP 8.0 and ensure compatibility with PHP 8.1 right away, while staying compatible with PHP 7.4 until end of year. This is not fun. PHP 8.x provides several features which allow for more concise code. I will not be able to use them.
This also means that for the time being I will produce code which you may find more verbose than necessary. While Constructor promotion is mostly about being less verbose, Readonly Properties and Enums kill some of the pro-method arguments in the eternal discussion if getter methods or public properties are more appropriate interfaces. Union Types and Intersection Types allow a flexibility of method interfaces which PHP 7.4 can only emulate. You can get far by type hints for static analysis combined with boilerplate guard code inside a method and dropping type hints all along or using insufficient surrogate interfaces. But it is really not shiny. Maintaining software which shows its age has its tradeoffs.