remove deprecated views from toc

Author: stevestein

docs/relational-databases/system-catalog-views/TOC.md

@@ -36,9 +36,6 @@
 ## [sys.resource_stats](sys-resource-stats-azure-sql-database.md)  
 ## [sys.resource_usage](sys-resource-usage-azure-sql-database.md)  
 ## [dbo.server_quotas](dbo-server-quotas-azure-sql-database.md)  
-## [dbo.slo_assignment_history](dbo-slo-assignment-history-azure-sql-database.md)  
-## [dbo.slo_database_objectives](dbo-slo-database-objectives-azure-sql-database.md)  
-## [dbo.slo_service_objectives](dbo-slo-service-objectives-azure-sql-database.md)  
 
 # [CLR Assembly](clr-assembly-catalog-views-transact-sql.md)  
 ## [sys.assemblies](sys-assemblies-transact-sql.md)