databases/cassandra[34]: allow building with JAVA_DEFAULT=21HEADmain

- ant needs to have JAVA_HOME set to the defined JAVA_VERSION

Reason:
when apache-ant pulls in openjdk21 as run dependency it will try
to use it if JAVA_HOME is not set. This gives the error:
"Java 15 has removed Nashorn, you must provide an engine for running
JavaScript yourself. GraalVM JavaScript currently is the preferred
option.", as cassandra needs an older Java version.

These ports have USES=ant, but override do-build and fetch. That is
why some special handling is needed.

PR:	272855
PR:	293050
Approved-by:	Angelo Polo (maintainer)

0 files changed, 0 insertions, 0 deletions