Docs: Remove references to group sync (#102599)

* remove references to group sync

* remove relfref and add new link

* remove relfref

* Update relfref

* remove relrefs and add admonitions

* fix URL

* remove relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* replace relrefs

* run prettier

---------

Co-authored-by: Irene Rodríguez <irene.rodriguez@grafana.com>

docs/sources/developers/http_api/_index.md

@@ -84,7 +84,6 @@ Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
 Grafana Enterprise includes all of the Grafana OSS APIs as well as the following APIs:
 
 - [Data source permissions API](datasource_permissions/)
-- [Group attribute sync API](group_attribute_sync/)
 - [License API](licensing/)
 - [Query and resource caching API](query_and_resource_caching/)
 - [Reporting API](reporting/)