Update toc.yml (Typo "Postgres extensions"→"PostgreSQL extensions")

https://github.com/MicrosoftDocs/azure-docs/edit/main/articles/azure-arc/data/toc.yml
https://docs.microsoft.com/en-us/azure/azure-arc/data/using-extensions-in-postgresql-hyperscale-server-group
#PingMSFTDocs

Author: hyoshioka0128

articles/azure-arc/data/toc.yml

@@ -165,7 +165,7 @@ items:
               href: configure-security-postgres-hyperscale.md
             - name: Manage server group (Azure Data Studio)
               href: manage-postgresql-hyperscale-server-group-with-azure-data-studio.md
-            - name: Use Postgres extensions
+            - name: Use PostgreSQL extensions
               href: using-extensions-in-postgresql-hyperscale-server-group.md
         - name: Migrate
           items: