Manual backport for the relevant parts of #11858 (#11885)

Manual backport for two of three files updated in #11858.

Note that the third file updated by #11858 has not been published to the
2.9 release, and thus is not part of this backport.

docs/sources/get-started/labels/structured-metadata.md

@@ -5,10 +5,6 @@ description: Describes how to enable structure metadata for logs and how to quer
 ---
 # What is structured metadata
 
-{{% admonition type="warning" %}}
-Structured metadata is an experimental feature and is subject to change in future releases of Grafana Loki. This feature is not yet available for Cloud Logs users.
-{{% /admonition %}}
-
 {{% admonition type="warning" %}}
 Structured metadata was added to chunk format V4 which is used if the schema version is greater or equal to `13`. (See [Schema Config]({{< relref "../../storage#schema-config" >}}) for more details about schema versions. )
 {{% /admonition %}}

docs/sources/release-notes/v2-9.md

@@ -9,6 +9,8 @@ Grafana Labs is excited to announce the release of Loki 2.9.0 Here's a summary o
 
 ## Features and enhancements
 
+- **Structured metadata**: The [Structured Metadata](https://grafana.com/docs/loki/latest/get-started/labels/structured-metadata/) feature, which was introduced as experimental in release 2.9.0, is generally available as of release 2.9.4.
+
 -  **Query Language Improvements**: Several improvements to the query language that speed up line parsing and regex matching. [PR #8646](https://github.com/grafana/loki/pull/8646), [PR #8659](https://github.com/grafana/loki/pull/8659), [PR #8724](https://github.com/grafana/loki/pull/8724), [PR #8734](https://github.com/grafana/loki/pull/8734), [PR #8739](https://github.com/grafana/loki/pull/8739), [PR #8763](https://github.com/grafana/loki/pull/8763), [PR #8890](https://github.com/grafana/loki/pull/8890), [PR #8914](https://github.com/grafana/loki/pull/8914)
 
 -  **Remote rule evaluation**: Rule evaluation can now be handled by queriers to improve speed. [PR #8744](https://github.com/grafana/loki/pull/8744) [PR #8848](https://github.com/grafana/loki/pull/8848)