test/cql-pytest: make run-cassandra work on new systems...
test/cql-pytest: make run-cassandra work on new systems...

with several Java versions

The test/cql-pytest/run-cassandra script runs our cql-pytest tests against
Cassandra. Today, Cassandra can only run correctly on Java 8 or 11
(see https://issues.apache.org/jira/browse/CASSANDRA-16895) but recent
Linux distributions have switched to newer versions of Java - e.g., on
my Fedora 36 installation, the default "java" is Java 17. Which can't
run Cassandra.

So what I do in this patch is to check if "java" has the right version,
and if it doesn't, it looks at several additional locations if it can
find a Java of the right version. By the way, we are sure that Java 8
must be installed because our install-dependencies.sh installs it.

After this patch, test/cql-pytest/run-cassandra resumes working on
Fedora 36.

Fixes #10946

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes #10947

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla