chore(website): add one more highlight (vectordotdev#23586)

Author: pront

website/cue/reference/releases/0.49.0.cue

@@ -17,6 +17,7 @@ releases: "0.49.0": {
 		- The `http` sink's `uri` and `request.headers` config fields now support templating, enabling dynamic construction based on event data.
 		- The `--watch-config` flag now also watches for changes in enrichment table files.
 		- Fixed a race condition that could cause negative values in the `vector_buffer_byte_size` and `vector_buffer_events` gauges.
+		- The `prometheus_remote_write` sink now offers a `expire_metrics_secs` config option. This fixes an issue where incremental metrics were preserved for the lifetime of Vector's runtime causing indefinite memory growth.
 		"""
 
 	changelog: [