MLE-24747 Small docs updates for versions

[rjrudin]

Not mentioning Confluent Platform versions anymore, so we don't have to be in the business of syncing with those. We just want to mention Kafka versions.

[github-actions]

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[Copilot]

Pull Request Overview

Updates system requirements documentation to remove Confluent Platform references and adjust stated Kafka/Java version requirements.

• Replaces prior Kafka/Confluent bullet with a combined Kafka 4.0+/Java 17+ plus historical 1.x connector requirements.
• Removes explanatory paragraph about untested earlier Kafka/Confluent versions.

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[Copilot]

This line conflates current and historical requirements, making it unclear which connector versions the Kafka 4.0/Java 17 requirement applies to. Recommend splitting into separate bullets (e.g., one for current connector version requirements and one for 1.x) and explicitly naming the connector version(s) to remove ambiguity: '* Connector 2.x requires Kafka or higher and Java 17 or higher.' '* Connector 1.x requires Kafka 2.5 or higher and Java 8 or higher.' Also verify that Kafka 4.0 is the correct minimum if it is officially released/supported; otherwise adjust to the latest supported major/minor.

Suggested change

	* Kafka 4.0 or higher, with Java 17 or higher. Releases 1.x of the MarkLogic Kafka connector require Kafka 2.5 or higher, which requires Java 8 or higher.
	* MarkLogic Kafka Connector 2.x requires Kafka 3.6 or higher and Java 17 or higher.
	* MarkLogic Kafka Connector 1.x requires Kafka 2.5 or higher and Java 8 or higher.