Update 2.4 release notes (#3319) (#3325)

* Update 2.4 release notes with features promoted to stable and deprecated config options removed

Signed-off-by: Marco Pracucci <marco@pracucci.com>

* Apply suggestions from code review

Co-authored-by: Ursula Kallio <ursula.kallio@grafana.com>

Signed-off-by: Marco Pracucci <marco@pracucci.com>
Co-authored-by: Ursula Kallio <ursula.kallio@grafana.com>
(cherry picked from commit d6bbc1e)

Co-authored-by: Marco Pracucci <marco@pracucci.com>

docs/sources/release-notes/v2.4.md

@@ -35,6 +35,11 @@ The highlights that follow include the top features, enhancements, and bugfixes
 
   The new configuration option allows you to set different limits between the received query maximum length (`-query-frontend.max-total-query-length`) and the maximum length of partial queries after splitting and sharding (`-store.max-query-length`).
 
+The following experimental features have been promoted to stable:
+
+- [Ruler's remote evaluation mode]({{< relref "../operators-guide/architecture/components/ruler/index.md#remote" >}})
+- [Memberlist cluster label verification]({{< relref "../operators-guide/configure/configuring-hash-rings.md#cluster-label-verification" >}})
+
 ### Helm chart improvements
 
 The `mimir-distributed` Helm chart is the best way to install Mimir on Kubernetes. As part of the Mimir 2.4 release, we’re also releasing version 3.2 of the `mimir-distributed` Helm chart.
@@ -95,6 +100,12 @@ In Grafana Mimir 2.4, the default values of the following configuration options
 - `-blocks-storage.tsdb.head-compaction-concurrency` has changed from `5` to `1`.
 - The hash-ring heartbeat period for distributors, ingesters, rulers, and compactors has increased from `5s` to `15s`.
 
+In Grafana Mimir 2.4, the following deprecated configuration options have been removed:
+
+- The YAML configuration option `limits.active_series_custom_trackers_config`.
+- The CLI flag `-ingester.ring.join-after` and its respective YAML configuration option `ingester.ring.join_after`.
+- The CLI flag `-querier.shuffle-sharding-ingesters-lookback-period` and its respective YAML configuration option `querier.shuffle_sharding_ingesters_lookback_period`.
+
 With Grafana Mimir 2.4, the [anonymous usage statistics tracking]({{< relref "../operators-guide/configure/about-anonymous-usage-statistics-reporting.md" >}}) is enabled by default.
 Mimir maintainers use this anonymous information to learn more about how the open source community runs Mimir and what the Mimir team should focus on when working on the next features and documentation improvements.
 If possible, we ask you to keep the usage reporting feature enabled.