Tombstone messages in kafka should trigger the conditional delete not throw an error

[andrecowie]

Lets say I create a sink:

curl -X POST -H "Content-Type: application/json" --data '
  {"name": "redis-sink-json",
   "config": {
     "connector.class":"com.redis.kafka.connect.RedisSinkConnector",
     "tasks.max":"1",
     "topics":"userinfo,userinfo.username",
     "redis.uri":"redis://redis:6379",
     "redis.command":"HSET",
     "redis.type":"HASH",
     "key.converter": "org.apache.kafka.connect.json.JsonConverter",
     "key.converter.schemas.enable": "false",
     "value.converter": "org.apache.kafka.connect.json.JsonConverter",
     "value.converter.schemas.enable": "false"
}}' http://localhost:8083/connectors -w "\n"

I want a tombstone record in kafka to trigger a delete in redis.

Currently It just throws an error and doesn't delete this change resolves this by allowing the conditional del function to run.
I also updated the java version to 21 from 17.

[andrecowie]

@jruaux Hey I see you are the maintainer, do you think you could comment on this PR keen to get this in. It is I think an important functionality to enable kafka tombstones to remove the value set in redis. If you want me to add a configuration param to be able to enable this let me know?