Java 21 support

[lyahim]

Hi @filiphr,

I would ask is it possible to update examples or create a new set which run on java 21.
We all love java 8 but it is a bit old. :)

If needed I can offer some time to support this operation, just I don't know which would be the best way.

Thank you,
Mihaly

[filiphr]

@lyahim MapStruct does support Java 21. Everything should work without any problems. However, I see your point. We can update the examples with Java 21 (or 17), as it is a good baseline anyways.