[fix][test] Fix flaky GeoReplicationTest.testTopicReplication

[void-ptr974]

Motivation

GeoReplicationTest.testTopicReplication can fail for the non-persistent variant because the test sends messages immediately after creating the producer and consumer. Non-persistent replication can drop messages when the remote replicator producer is not connected yet, so the test can time out waiting for messages on the remote cluster.

Fixes #15913.

Modifications

• Wait for every partition replicator to the remote cluster to be present and connected before sending messages for the non-persistent variant.
• Keep the persistent and non-persistent variants in the existing data provider.
• Use constants for the partition and message counts.
• Increase the test timeout to account for the explicit replicator readiness wait.

Verification

• ./gradlew :tests:integration:compileTestJava --max-workers=1
• ./gradlew :tests:integration:checkstyleTest --max-workers=1

The container integration test was not run locally because the local Docker context is not available to Testcontainers.