[DOCS] Update 8.1.0 release notes (#84185) (#84302)

(cherry picked from commit 297b69ed6cce14159158f50e574c27e9904aa5f5)

# Conflicts:
#	docs/reference/release-notes/8.1.asciidoc

Co-authored-by: Ievgen Degtiarenko <ievgen.degtiarenko@elastic.co>

docs/changelog/83290.yaml

@@ -1,5 +1,5 @@
 pr: 83290
-summary: Update YAML Rest tests to check for product header on all responses
+summary: Update YAML REST tests to check for product header on all responses
 area: Infra/REST API
 type: enhancement
 issues: []

docs/reference/release-notes/8.1.asciidoc

@@ -35,14 +35,25 @@ Autoscaling::
 
 Geo::
 * Handle bounds properly when grid tiles crosses the dateline {es-pull}83348[#83348] (issue: {es-issue}83299[#83299])
+* `GeometryNormalizer` should not fail if it cannot compute signed area {es-pull}84051[#84051] (issue: {es-issue}83946[#83946])
 
 Infra/Core::
+* Always re-run Feature migrations which have encountered errors {es-pull}83918[#83918] (issue: {es-issue}83917[#83917])
 * Copy `trace.id` in threadcontext stash {es-pull}83218[#83218]
+* Preserve context in `ResultDeduplicator` {es-pull}84038[#84038] (issue: {es-issue}84036[#84036])
+* Update system index mappings if `_meta` is null {es-pull}83896[#83896] (issue: {es-issue}83890[#83890])
+
+Infra/REST API::
+* Do not allow safelisted media types on Content-Type {es-pull}83448[#83448]
 
 Infra/Scripting::
 * Fix duplicated allow lists upon script engine creation {es-pull}82820[#82820] (issue: {es-issue}82778[#82778])
 * Fix plumbing in double and keyword runtime fields for the scripting fields API {es-pull}83392[#83392]
 
+Ingest::
+* Fix `GeoIpDownloader` startup during rolling upgrade {es-pull}84000[#84000]
+* Short circuit date patterns after first match {es-pull}83764[#83764]
+
 Machine Learning::
 * Correctly capture min stats for `inference.ingest_processors` in ML usage {es-pull}82352[#82352]
 * Fail queued inference requests with cause if the process crashes {es-pull}81584[#81584]
@@ -76,6 +87,7 @@ Snapshot/Restore::
 * Adjust `LinuxFileSystemNatives.allocatedSizeInBytes` for aarch64 architectures {es-pull}81376[#81376] (issues: {es-issue}80437[#80437], {es-issue}81362[#81362])
 * Distinguish "missing repository" from "missing repository plugin" {es-pull}82457[#82457] (issue: {es-issue}81758[#81758])
 * Move get snapshots serialization to management pool {es-pull}83215[#83215]
+* Preserve context in `snapshotDeletionListeners` {es-pull}84089[#84089] (issue: {es-issue}84036[#84036])
 
 TSDB::
 * Fix time series timestamp meta missing {es-pull}80695[#80695]
@@ -152,6 +164,7 @@ Infra/Core::
 
 Infra/REST API::
 * Allow for customised content-type validation {es-pull}80906[#80906] (issue: {es-issue}80482[#80482])
+* Update YAML REST tests to check for product header on all responses {es-pull}83290[#83290]
 
 Infra/Scripting::
 * Add '$' syntax as a shortcut for 'field' in Painless {es-pull}80518[#80518]