Release notes for 8.16.1 (elastic#16691) (elastic#16708)

Co-authored-by: logstashmachine <43502315+logstashmachine@users.noreply.github.com>
Co-authored-by: João Duarte <jsvd@users.noreply.github.com>
Co-authored-by: Karen Metts <35154725+karenzone@users.noreply.github.com>
(cherry picked from commit 8b97c05)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

docs/static/releasenotes.asciidoc

@@ -3,6 +3,7 @@
 
 This section summarizes the changes in the following releases:
 
+* <<logstash-8-16-1,Logstash 8.16.1>>
 * <<logstash-8-16-0,Logstash 8.16.0>>
 * <<logstash-8-15-4,Logstash 8.15.4>>
 * <<logstash-8-15-3,Logstash 8.15.3>>
@@ -70,6 +71,41 @@ This section summarizes the changes in the following releases:
 * <<logstash-8-0-0-alpha1,Logstash 8.0.0-alpha1>>
 
 
+[[logstash-8-16-1]]
+=== Logstash 8.16.1 Release Notes
+
+[[notable-8-16-1]]
+==== Notable issues fixed
+
+* PipelineBusV2 deadlock proofing: We fixed an issue that could cause a deadlock when the pipeline-to-pipeline feature was in use, causing pipelines (and consequently) {ls} to never terminate https://github.com/elastic/logstash/pull/16680[#16680]
+
+==== Plugins
+
+*Elastic_integration Filter - 0.1.16*
+
+* Reflect the Elasticsearch GeoIP changes into the plugin and sync with Elasticsearch 8.16 branch https://github.com/elastic/logstash-filter-elastic_integration/pull/170[#170]
+
+*Xml Filter - 4.2.1*
+
+* patch rexml to improve performance of multi-threaded xml parsing https://github.com/logstash-plugins/logstash-filter-xml/pull/84[#84]
+
+*Beats Input - 6.9.1*
+
+* Upgrade netty to 4.1.115 https://github.com/logstash-plugins/logstash-input-beats/pull/507[#507]
+
+*Http Input - 3.9.2*
+
+* Upgrade netty to 4.1.115 https://github.com/logstash-plugins/logstash-input-http/pull/183[#183]
+
+*Tcp Input - 6.4.4*
+
+* Upgrade netty to 4.1.115 https://github.com/logstash-plugins/logstash-input-tcp/pull/227[#227]
+
+*Http Output - 5.7.1*
+
+* Added new development `rackup` dependency to fix tests 
+
+
 [[logstash-8-16-0]]
 === Logstash 8.16.0 Release Notes