removing doc

Author: aahill

articles/ai-services/openai/how-to/network-security-perimeter.md

@@ -235,8 +235,6 @@ items:
         href: encrypt-data-at-rest.md
       - name: Managed identity
         href: ./how-to/managed-identity.md
-      - name: Add an Azure OpenAI service to a network security perimeter
-        href: ./how-to/network-security-perimeter.md
   - name: Service management
     items:
       - name: Resource creation & model deployment