Quite some time ago jandex project was moved from wildfly to smallrye project. As a result, maven coordinates have also changed.
See https://smallrye.io/blog/jandex-3-0-0/ for more details

We still use very old jboss jandex pluing, which may cause compilation failures on newer JDKs.
We should switch to up-to-date smallrye jandex pluing:

<groupId>io.smallrye</groupId>
<artifactId>jandex-maven-plugin</artifactId>
<version>3.4.0</version>