Deprecation notification about async import (#12244)

Author: manuel-sommer

docs/content/en/open_source/upgrading/2.46.md

@@ -5,6 +5,10 @@ weight: -20250407
 description: Import Payload Changes
 ---
 
+### Asynchronous Import deprecation in 2.47.0
+
+Please note that asynchronous import is already deprecated and will be removed in version 2.47.0. If you haven't migrated from this feature yet, we recommend doing so.
+
 ### Import / Reimport Statistics Delta
 
 Following a successful import or reimport, a JSON blob for `statistics` is generated to provide the differential of finding activity.