Remove API-REF docs from DBSS

Reviewed-by: Gode, Sebastian <sebastian.gode@t-systems.com>
Co-authored-by: tischrei <tino.schreiber@t-systems.com>
Co-committed-by: tischrei <tino.schreiber@t-systems.com>

otc_metadata/data/documents/dbss-api-ref.yaml

@@ -1,8 +0,0 @@
----
-html_location: docs/dbss/api-ref
-link: /database-security-service/api-ref/
-pdf_name: dbss-api-ref
-rst_location: api-ref/source
-service_type: dbss
-title: API Reference
-type: api-ref