test with jdk 21

[pjfanning]

I don't want to test every possible combination of setup but I think testing the most recent Java LTS release is useful.

[pjfanning]

With Java 21, we get a couple of test failures but they could be flaky tests. Needs more investigation.

But we so see:

[WARN] [10/06/2024 11:23:46.211] [ReconnectSpec-pekko.persistence.cassandra.default-dispatcher-7] [CassandraReadJournal] EventsByTag eventual consistency set below 1 second. This is likely to result in missed events. See reference.conf for details.
Starting Cassandra on port client port: 37677 storage port 46123 host 127.0.0.1 java version 21.0.4+7-LTS
java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release
Exception (java.lang.UnsupportedOperationException) encountered during startup: The Security Manager is deprecated and will be removed in a future release
	at java.base/java.lang.System.setSecurityManager(System.java:430)
	at org.apache.cassandra.security.ThreadAwareSecurityManager.install(ThreadAwareSecurityManager.java:75)
	at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:192)
	at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:602)
	at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:691)
[DEBUG] [10/06/2024 11:23:59.517] [Migrator-pekko.actor.default-dispatcher-8] [pekko://Migrator/user/$a] Update tag scanning [(pOne,2),(pTwo,2)]
Error:  [10/06/2024 11:24:06.223] [ReconnectSpec-pekko.actor.default-dispatcher-6] [pekko://ReconnectSpec/user/$a] Persistence failure when replaying events for persistenceId [pid]. Last known sequence number [0] (org.apache.pekko.pattern.CircuitBreaker$$anon$13: Circuit Breaker Timed out.)
[INFO] [pekkoDeadLetter][10/06/2024 11:24:06.224] [ReconnectSpec-pekko.actor.default-dispatcher-9] [pekko://ReconnectSpec/user/$a] Message [java.lang.String] from Actor[pekko://ReconnectSpec/system/testActor-1810#1819287665] to Actor[pekko://ReconnectSpec/user/$a#1139777581] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[pekko://ReconnectSpec/user/$a#1139777581] may have terminated unexpectedly. This logging can be turned off or adjusted with configuration settings 'pekko.log-dead-letters' and 'pekko.log-dead-letters-during-shutdown'.
[info] - must start with system off *** FAILED *** (45 seconds, 199 milliseconds)
[info]   java.lang.RuntimeException: Cassandra did not start within 45 seconds
[info]   at org.apache.pekko.persistence.cassandra.testkit.CassandraLauncher$.tryConnect$1(CassandraLauncher.scala:423)
[info]   at org.apache.pekko.persistence.cassandra.testkit.CassandraLauncher$.waitForCassandraToListen(CassandraLauncher.scala:427)
[info]   at org.apache.pekko.persistence.cassandra.testkit.CassandraLauncher$.startForked(CassandraLauncher.scala:350)
[info]   at org.apache.pekko.persistence.cassandra.testkit.CassandraLauncher$.start(CassandraLauncher.scala:299)
[info]   at org.apache.pekko.persistence.cassandra.testkit.CassandraLauncher$.start(CassandraLauncher.scala:226)
[info]   at org.apache.pekko.persistence.cassandra.ReconnectSpec.$anonfun$new$2(ReconnectSpec.scala:60)