Add release notes for 6.8.22

Author: mark-vieira

docs/reference/release-notes.asciidoc

@@ -5,6 +5,7 @@
 --
 This section summarizes the changes in each release.
 
+* <<release-notes-6.8.22>>
 * <<release-notes-6.8.21>>
 * <<release-notes-6.8.20>>
 * <<release-notes-6.8.19>>

docs/reference/release-notes/6.8.asciidoc

@@ -1,3 +1,14 @@
+[[release-notes-6.8.22]]
+== {es} version 6.8.22
+
+[[upgrade-6.8.22]]
+[float]
+=== Upgrades
+
+Infra/Logging::
+* Upgrade to log4j 2.17.0 {es-pull}81902[#81902]
+
+
 [[release-notes-6.8.21]]
 == {es} version 6.8.21