JCov and Java 21

[Clemens Ballarin]

I figured that I can build a version of JCov compatible with Java 21 
from https://github.com/openjdk/jcov by setting the correct ASM version 
9.5. This is nice! What puzzles me is that there haven't been any 
release tags since 2018. Certainly the current revison is somewhere 
mid-development and, while it works, isn't really ideal to use. Are you 
planning a "Java 21" version?

Clemens