4.0.7 release notes

(cherry picked from commit 9857128)

Author: michaelklishin

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+## RabbitMQ 4.0.7
+
+RabbitMQ `4.0.7` is a maintenance release in the `4.0.x` [release series](https://www.rabbitmq.com/release-information).
+
+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).
+
+It is **strongly recommended** that you read [4.0 release notes](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.0.1)
+in detail if upgrading from a version prior to `4.0.0`.
+
+
+### Minimum Supported Erlang Version
+
+This release requires Erlang 26 and supports Erlang versions up to `27.2.x`.
+[RabbitMQ and Erlang/OTP Compatibility Matrix](https://www.rabbitmq.com/docs/which-erlang) has more details on
+Erlang version requirements for RabbitMQ.
+
+Nodes **will fail to start** on older Erlang releases.
+
+
+## Changes Worth Mentioning
+
+Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://github.com/rabbitmq/rabbitmq-server/tree/v4.0.x/release-notes).
+
+### Core Broker
+
+#### Bug Fixes
+
+ * Classic queue message store did not remove segment files with large messages (over 4 MB) in some cases.
+
+   GitHub issue: [#13430](https://github.com/rabbitmq/rabbitmq-server/pull/13430)
+
+ * A node with Khepri enabled would fail to start if its metadata store contained an exclusive queue
+   with at least one binding.
+
+   GitHub issuew: [#13352](https://github.com/rabbitmq/rabbitmq-server/issues/13352), [#13394](https://github.com/rabbitmq/rabbitmq-server/pull/13394)
+
+#### Enhancements
+
+ * Reduced memory usage and GC pressure for workloads where large (4 MB or greater) messages were published to classic queues.
+
+   Contributed by @gomoripeti.
+
+   GitHub issue: [#13375](https://github.com/rabbitmq/rabbitmq-server/pull/13375)
+
+
+### CLI Tools
+
+#### Deprecations
+
+ * `rabbitmq-streams set_stream_retention_policy` is now a no-op.
+
+   It was a leftover from the early days of streams. The modern and optimal way of configuring
+   stream retention is [via a policy](https://www.rabbitmq.com/docs/streams#retention).
+
+   GitHub issue: [#13358](https://github.com/rabbitmq/rabbitmq-server/pull/13358)
+
+
+### Prometheus Plugin
+
+#### Enhancements
+
+ * New labels make it possible to differentiate between the metrics with the same name scraped from the aggregated
+   metric endpoint and the [per-object metric endpoint](https://www.rabbitmq.com/docs/prometheus#metric-aggregation).
+
+   GitHub issue: [#13239](https://github.com/rabbitmq/rabbitmq-server/pull/13239)
+
+
+### Management Plugin
+
+#### Bug Fixes
+
+ * Who help tooltips were not updated for 4.0.x.
+
+   GitHub issue: [#13357](https://github.com/rabbitmq/rabbitmq-server/pull/13357)
+
+#### Enhancements
+
+ * Consumer count is a new column that can be enabled for the channels table on the tab of the same name.
+
+   Contributed by @gomoripeti.
+
+   GitHub issue: [#13258](https://github.com/rabbitmq/rabbitmq-server/pull/13258)
+
+
+### Caching Authentication and Authorization Backend Plugin
+
+#### Enhancements
+
+ * `rabbitmqctl clear_auth_backend_cache` is a new command that clears the [cache maintained by the plugin](https://www.rabbitmq.com/docs/auth-cache-backend).
+
+
+### Dependency Changes
+
+ * `ra` was upgraded to [`2.15.2`](https://github.com/rabbitmq/ra/releases)
+
+
+## Source Code Archives
+
+To obtain source code of the entire distribution, please download the archive named `rabbitmq-server-4.0.7.tar.xz`
+instead of the source tarball produced by GitHub.