Updated CHANGELOG and docs with 8.4

Author: ezimuel

CHANGELOG.md

@@ -1,3 +1,15 @@
+## Release 8.4.0
+
+- Added a `ClientInterface` to simplify the mock of the Client,
+  this is a fix for [#1227](https://github.com/elastic/elasticsearch-php/issues/1227)
+  [#1249](https://github.com/elastic/elasticsearch-php/pull/1249)
+- Added the support of Symfony HTTP client, fixing the issue [#1241](https://github.com/elastic/elasticsearch-php/issues/1241)
+  [#1243](https://github.com/elastic/elasticsearch-php/pull/1243)
+- Added the API compatibility header
+  [#1233](https://github.com/elastic/elasticsearch-php/pull/1233)
+- Updated APIs for [Elasticsearch 8.4](https://github.com/elastic/elasticsearch/releases/tag/v8.4.0)
+  [7815caa](https://github.com/elastic/elasticsearch-php/commit/7815caac3d9342f13555481bd03ceb8d9c49a881)
+
 ## Release 8.3.0
 
 - Updated APIs for [Elasticsearch 8.3](https://github.com/elastic/elasticsearch/releases/tag/v8.3.0)

docs/release-notes.asciidoc

@@ -1,6 +1,7 @@
 [[release-notes]]
 == Release notes
 
+* <<rn-8-4-0>>
 * <<rn-8-3-0>>
 * <<rn-8-2-0>>
 * <<rn-8-1-0>>
@@ -35,6 +36,19 @@
 * <<rn-7-0-1>>
 * <<rn-7-0-0>>
 
+[discrete]
+[[rn-8-4-0]]
+=== 8.4.0
+
+* Added a `ClientInterface` to simplify the mock of the Client,
+  this is a fix for https://github.com/elastic/elasticsearch-php/issues/1227[#1227]
+  https://github.com/elastic/elasticsearch-php/pull/1249[#1249]
+* Added the support of Symfony HTTP client, fixing the issue https://github.com/elastic/elasticsearch-php/issues/1241[#1241]
+  https://github.com/elastic/elasticsearch-php/pull/1243[#1243]
+* Added the API compatibility header
+  https://github.com/elastic/elasticsearch-php/pull/1233[#1233]
+* Updated the API endpoints to Elasticserach 8.4.0
+
 [discrete]
 [[rn-8-3-0]]
 === 8.3.0