[release-12.0.2] Docs: Document `remote_cache` is only used if a remote database is used (#106791)

Docs: Document `remote_cache` is only used if a remote database is used (#104779)

* Document `remote_cache` is only used if a remote database is used

* Update _index.md

---------


(cherry picked from commit 19a65a4865)

Co-authored-by: Mathias Petermann <mathias.petermann@gmail.com>
Co-authored-by: Jacob Valdez <jacob.valdez@grafana.com>

docs/sources/setup-grafana/configure-grafana/_index.md

@@ -479,7 +479,11 @@ Set to `true` to add metrics and tracing for database queries. The default value
 
 ### `[remote_cache]`
 
-Caches authentication details and session information in the configured database, Redis or Memcached. This setting does not configure [Query Caching in Grafana Enterprise](../../administration/data-source-management/#query-and-resource-caching).
+Caches authentication tokens and other temporary authentication-related data in the configured database, Redis, or Memcached. This setting doesn't configure [Query Caching in Grafana Enterprise](../../administration/data-source-management/#query-and-resource-caching).
+
+{{< admonition type="note" >}}
+This setting doesn't control user session storage. User sessions are _always_ stored in the main database configured in `[database]` regardless of your `[remote_cache]` settings.
+{{< /admonition >}}
 
 #### `type`