Update 4.0.0 release notes

(cherry picked from commit 2c753f6)

release-notes/4.0.0.md

@@ -1,6 +1,6 @@
-## RabbitMQ 4.0.0-beta.3
+## RabbitMQ 4.0.0-beta.2
 
-RabbitMQ `4.0.0-beta.3` is a preview of a new major release.
+RabbitMQ `4.0.0-beta.2` is a preview of a new major release.
 
 Starting June 1st, 2024, community support for this series will only be provided to [regularly contributing users](https://github.com/rabbitmq/rabbitmq-server/blob/main/COMMUNITY_SUPPORT.md) and those who hold a valid [commercial support license](https://tanzu.vmware.com/rabbitmq/oss).
 
@@ -73,4 +73,20 @@ periods of time (no more than a few hours).
 
 ### Recommended Post-upgrade Procedures
 
-TBD
+TBD
+
+
+## Changes Worth Mentioning
+
+TBD
+
+
+### Dependency Changes
+
+ * Ra was [upgraded to `2.13.1`](https://github.com/rabbitmq/ra/releases)
+ * Khepri was [upgraded to `0.14.0`](https://github.com/rabbitmq/khepri/releases)
+
+## Source Code Archives
+
+To obtain source code of the entire distribution, please download the archive named `rabbitmq-server-3.13.4.tar.xz`
+instead of the source tarball produced by GitHub.