Preparing 9.1.0 release with proxy support and build with ES 9.1 (#321)

Author: mashhurs

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 9.1.0
+  - Introduces `proxy` param to support proxy [#316](https://github.com/elastic/logstash-filter-elastic_integration/pull/316)
+  - Embeds Ingest Node components from Elasticsearch 9.1
+
 ## 9.0.0
   - Embeds Ingest Node components from Elasticsearch 9.0, no functional change [#291](https://github.com/elastic/logstash-filter-elastic_integration/pull/291)