Update 3.9.22 release notes

(cherry picked from commit e3236c9)

Author: michaelklishin

release-notes/3.9.22.md

@@ -39,6 +39,17 @@ Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://
    GitHub issue: [#4539](https://github.com/rabbitmq/rabbitmq-server/issues/4539)
 
 
+## Shovel plugin
+
+### Bug Fixes
+
+ * Shovels now handle consumer delivery timeouts gracefully and restart.
+
+   Contributed by @Haster2004.
+
+   GitHub issue: [#5243](https://github.com/rabbitmq/rabbitmq-server/pull/5243)
+
+
 ## Dependency Upgrades
 
 None in this release.