Update 3.13.0 release notes for beta.3

Author: michaelklishin

release-notes/3.13.0.md

@@ -1,6 +1,6 @@
-## RabbitMQ 3.13.0-beta.2
+## RabbitMQ 3.13.0-beta.3
 
-RabbitMQ `3.13.0-beta.2` is a preview of a new feature release.
+RabbitMQ `3.13.0-beta.3` is a preview of a new feature release.
 
 ## Highlights
 
@@ -127,7 +127,7 @@ Release notes are kept under [rabbitmq-server/release-notes](https://github.com/
 
    Contributed by @luos (Erlang Solutions).
 
-   GitHub issue: [#8834](https://github.com/rabbitmq/rabbitmq-server/pull/8834)
+   GitHub issues: [#8834](https://github.com/rabbitmq/rabbitmq-server/pull/8834), [#8927](https://github.com/rabbitmq/rabbitmq-server/pull/8927)
 
 #### Bug Fixes