Release notes for 8.18.4 (#17783)

Author: github-actions[bot]

docs/static/releasenotes.asciidoc

@@ -3,6 +3,7 @@
 
 This section summarizes the changes in the following releases:
 
+* <<logstash-8-18-4,Logstash 8.18.4>>
 * <<logstash-8-18-3,Logstash 8.18.3>>
 * <<logstash-8-18-2,Logstash 8.18.2>>
 * <<logstash-8-18-1,Logstash 8.18.1>>
@@ -89,6 +90,27 @@ This section summarizes the changes in the following releases:
 * <<logstash-8-0-0-alpha2,Logstash 8.0.0-alpha2>>
 * <<logstash-8-0-0-alpha1,Logstash 8.0.0-alpha1>>
 
+[[logstash-8-18-4]]
+=== Logstash 8.18.4 Release Notes
+
+[[notable-8-18-4]]
+==== Notable issues fixed
+
+* Significantly improves write speeds to the persistent queue (PQ) when a pipeline's workers are caught up with already-written events. https://github.com/elastic/logstash/pull/17789[#17789]
+* Eliminated log warning about unknown gauge metric type when using pipeline-to-pipeline. https://github.com/elastic/logstash/pull/17721[#17721]
+
+[[featured-8-18-4]]
+==== New features and enhancements
+
+Logstash OSS and Full docker images are now based on Ubuntu 24.04.
+
+[[plugins-8-18-4]]
+==== Plugins
+
+*Elastic_integration Filter - 8.17.2*
+
+* Introduces `proxy` config to support proxy URI to connect to Elasticsearch. https://github.com/elastic/logstash-filter-elastic_integration/pull/317[#317]
+
 [[logstash-8-18-3]]
 === Logstash 8.18.3 Release Notes
 
@@ -3488,4 +3510,4 @@ We have added another flag to the Benchmark CLI to allow passing a data file wit
 This feature allows users to run the Benchmark CLI in a custom test case with a custom config and a custom dataset. https://github.com/elastic/logstash/pull/12437[#12437]
 
 ==== Plugin releases
-Plugins align with release 7.14.0
+Plugins align with release 7.14.0