Update docs for v8.4.2 release (#90084)

Update docs for v8.4.2 release

docs/changelog/89472.yaml

@@ -1,5 +1,5 @@
 pr: 89472
-summary: Fixing the conditions for fetching remote master history
+summary: Fix the conditions for fetching remote master history
 area: Health
 type: bug
 issues:

docs/changelog/89535.yaml

@@ -1,5 +1,5 @@
 pr: 89535
-summary: Update openjdk to 18.0.2.1
+summary: Update OpenJDK to 18.0.2.1
 area: Packaging
 type: upgrade
 issues:

docs/changelog/89632.yaml

@@ -1,5 +1,5 @@
 pr: 89632
-summary: Fix pipeline id not present in ingest metadata inside `on_failure` block
+summary: Fix pipeline `id` not present in ingest metadata inside `on_failure` block
 area: Ingest Node
 type: bug
 issues: []

docs/changelog/89768.yaml

@@ -1,5 +1,5 @@
 pr: 89768
-summary: Autoscaling after clone fix
+summary: Fix issue with autoscaling after a clone or split
 area: Autoscaling
 type: bug
 issues:

docs/changelog/89934.yaml

@@ -1,5 +1,5 @@
 pr: 89934
-summary: Fix deadlock bug exposed by the test
+summary: Implement fix to terminate file Watcher thread to avoid deadlock
 area: Infra/Core
 type: bug
 issues: []

docs/reference/release-notes.asciidoc

@@ -6,6 +6,7 @@
 
 This section summarizes the changes in each release.
 
+* <<release-notes-8.4.2>>
 * <<release-notes-8.4.1>>
 * <<release-notes-8.4.0>>
 * <<release-notes-8.3.3>>
@@ -30,6 +31,7 @@ This section summarizes the changes in each release.
 
 --
 
+include::release-notes/8.4.2.asciidoc[]
 include::release-notes/8.4.1.asciidoc[]
 include::release-notes/8.4.0.asciidoc[]
 include::release-notes/8.3.3.asciidoc[]

docs/reference/release-notes/8.4.2.asciidoc

@@ -0,0 +1,70 @@
+[[release-notes-8.4.2]]
+== {es} version 8.4.2
+
+coming[8.4.2]
+
+Also see <<breaking-changes-8.4,Breaking changes in 8.4>>.
+
+[[bug-8.4.2]]
+[float]
+=== Bug fixes
+
+Allocation::
+* Fix debug mode in `MaxRetryAllocationDecider` {es-pull}89973[#89973]
+
+Authentication::
+* Fix double sending of response in `TransportOpenIdConnectPrepareAuthenticationAction` {es-pull}89930[#89930]
+
+Autoscaling::
+* Fix issue with autoscaling after a clone or split {es-pull}89768[#89768] (issue: {es-issue}89758[#89758])
+
+Health::
+* Fix the conditions for fetching remote master history {es-pull}89472[#89472] (issue: {es-issue}89431[#89431])
+
+ILM+SLM::
+* Copy `isHidden` during ILM alias swap {es-pull}89650[#89650] (issue: {es-issue}89604[#89604])
+
+Infra/Core::
+* Extend the date rounding logic to be conditional {es-pull}89693[#89693] (issues: {es-issue}89096[#89096], {es-issue}58986[#58986])
+* Fix `FileSettingsService` hang on error update {es-pull}89630[#89630]
+* Implement fix to terminate file Watcher thread to avoid deadlock {es-pull}89934[#89934]
+
+Ingest Node::
+* Fix pipeline `id` not present in ingest metadata inside `on_failure` block {es-pull}89632[#89632]
+
+Machine Learning::
+* Fix memory leak in `TransportDeleteExpiredDataAction` {es-pull}89935[#89935]
+
+Network::
+* Fix memory leak when double invoking `RestChannel.sendResponse` {es-pull}89873[#89873]
+
+Ranking::
+* Avoid negative scores with `cross_fields` type {es-pull}89016[#89016] (issue: {es-issue}44700[#44700])
+
+Rollup::
+* Fork `TransportRollupCapsAction` to MANAGEMENT POOL {es-pull}89803[#89803]
+
+Search::
+* Empty intervals needs to start in position -1 {es-pull}89962[#89962] (issue: {es-issue}89789[#89789])
+
+Transform::
+* Scheduler concurrency fix {es-pull}89716[#89716] (issue: {es-issue}88991[#88991])
+
+[[enhancement-8.4.2]]
+[float]
+=== Enhancements
+
+Allocation::
+* Log unsuccessful attempts to get credentials from web identity tokens {es-pull}88241[#88241]
+
+Health::
+* Add delayed allocation diagnosis case to shards availability indicator {es-pull}89056[#89056]
+
+[[upgrade-8.4.2]]
+[float]
+=== Upgrades
+
+Packaging::
+* Update OpenJDK to 18.0.2.1 {es-pull}89535[#89535] (issue: {es-issue}89531[#89531])
+
+