revert(plugin-server): bump node-rdkafka to 2.18.0

[bretthoerner]

… 2.3.0) (#18228)"

This reverts commit 4756d47.

Problem

Changes

👉 Stay up-to-date with PostHog coding conventions for a smoother review.

How did you test this code?

[bretthoerner]

I can't tell for sure but it feels like this is failing (pre-revert):

posthog/plugin-server/src/main/ingestion-queues/session-recording/utils.ts

Lines 39 to 50 in b118d4f

	batchConsumer.consumer.queryWatermarkOffsets(
	KAFKA_SESSION_RECORDING_SNAPSHOT_ITEM_EVENTS,
	partition,
	(err, offsets) => {
	if (err) {
	status.error('🔥', 'Failed to query kafka watermark offsets', err)
	return reject()
	}
	resolve([partition, offsets.highOffset])
	}
	)