Replace accidentally removed line.

Author: map-blasterson

src/azure-cli/azure/cli/command_modules/network/private_link_resource_and_endpoint_connections/custom.py

@@ -86,6 +86,7 @@ def register_providers():
     _register_one_provider('Microsoft.App/managedEnvironments', '2024-02-02-preview', True)
     _register_one_provider('Microsoft.FluidRelay/fluidRelayServers', '2025-03-10-preview', True)
     _register_one_provider('Microsoft.VideoIndexer/accounts', '2025-04-01', True)
+    _register_one_provider('Microsoft.Security/privateLinks', '2025-09-01-preview', True)
     _register_one_provider('Microsoft.Maps/accounts', '2023-12-01-preview', True)