Update prepare-to-upgrade.md

Adding a small recommendation that we have always shared for major upgrades.

If the user is already on the latest minor (8.18.x) it's also recommended to upgrade to 8.18.latest before upgrading to 9.x, as there could be fixes and improvements on upgrade assistant and other components.

A clear example of this could be elastic/stack-docs#3024

Author: eedugon

deploy-manage/upgrade/prepare-to-upgrade.md

@@ -19,7 +19,9 @@ Upgrading from a release candidate build, such as 9.0.0-rc1, is unsupported. Use
 
 To upgrade from 8.17.0 or earlier to 9.0.0, you must first upgrade to the latest 8.18 patch release. This allows you to use the [Upgrade Assistant](prepare-to-upgrade/upgrade-assistant.md) to identify and resolve issues, reindex indices created before 8.0.0, and perform a rolling upgrade. Upgrading to the latest 8.18 patch release is required even if you choose a full {{es}} cluster restart. If you're using 7.x and earlier, you may need to complete multiple upgrades or perform a full-cluster restart to reach the latest 8.18 patch release before upgrading to 9.0.0.
 
-Alternatively, you can create a 9.0.0 deployment and reindex from remote. For more information, refer to [Reindex to upgrade](#reindex-to-upgrade).
+If you are already running an 8.18.x version, it's also recommended to upgrade to the latest 8.18 patch release before upgrading to 9.x, as that will ensure the latest version of the upgrade assistant will be used, together with other possible bug fixes that could have implications in the upgrade.
+
+Alternatively to upgrading the cluster, you can create a 9.0.0 deployment and reindex from remote. For more information, refer to [Reindex to upgrade](#reindex-to-upgrade).
 
 :::{note}
 For flexible upgrade scheduling, 8.18.0 {{beats}} and {{ls}} are compatible with 9.x {{es}}.