RANGER-5658: Remove obsolete atlas.kafka.zookeeper.connect requirement from Tag Sync

[ramackri]

Summary

Remove the legacy atlas.kafka.zookeeper.connect configuration requirement from Ranger Tag Sync's Atlas Kafka source (RANGER-5658).

Tag Sync consumes Atlas entity notifications via kafka-clients using atlas.kafka.bootstrap.servers and atlas.kafka.entities.group.id. The zookeeper.connect property was never used by Atlas 2.4 KafkaNotification for consumer creation; Ranger only validated that it was set. With Kafka 3.9.x and KRaft brokers, clients do not use ZooKeeper for consumption.

Changes

• Drop TAGSYNC_ATLAS_ZOOKEEPER_ENDPOINT constant and startup validation from AtlasTagSource
• Extract validateRequiredAtlasKafkaProperties() for unit testing
• Remove TAG_SOURCE_ATLAS_KAFKA_ZOOKEEPER_CONNECT from install.properties, installprop2xml.properties, and setup.py

Out of scope

• Tag Sync HA (ranger-tagsync.server.ha.zookeeper.*) — unchanged; still requires ZooKeeper when HA is enabled
• Atlas REST tag source — unaffected

Upgrade note

Existing deployments may still have atlas.kafka.zookeeper.connect in conf/atlas-application.properties; it is harmless and can be removed manually. New installs no longer generate or require it.

Test plan

Unit tests

mvn test -pl tagsync -Drat.skip=true \
  -Dtest=AtlasTagSourceConfigTest \
  -Dsurefire.failIfNoSpecifiedTests=false

Test	Verifies
validateRequiredAtlasKafkaProperties_acceptsBootstrapAndGroupWithoutZookeeper	No ZK property required when bootstrap + group are set
validateRequiredAtlasKafkaProperties_rejectsMissingBootstrapServers	Bootstrap servers still mandatory
validateRequiredAtlasKafkaProperties_rejectsMissingConsumerGroup	Consumer group still mandatory

• AtlasTagSourceConfigTest — 3 tests, 0 failures (local run)
• Fresh Tag Sync install with Atlas Kafka source — conf/atlas-application.properties has no zookeeper.connect
• Tag Sync starts and consumes Atlas entity notifications from Kafka 3.9.x (KRaft)
• Upgrade: existing install with legacy zookeeper.connect still starts
• Tag Sync HA smoke test (if ranger-tagsync.server.ha.enabled=true) — leader election unchanged