Remove release note (#17966)

This feature did not make it in the final BC. Remove it.

Author: donoghuc

docs/release-notes/index.md

@@ -23,9 +23,7 @@ To check for security updates, go to [Security announcements for the Elastic sta
 
 ## 9.1.2 [logstash-9.1.2-release-notes]
 
-### Features and enhancements [logstash-9.1.2-features-enhancements]
-
-* Logging improvement while handling exceptions in the pipeline, ensuring that chained exceptions propagate enough information to be actionable. [#17935](https://github.com/elastic/logstash/pull/17935)
+No user-facing changes in Logstash core.
 
 ### Plugins [logstash-plugin-9.1.2-changes]