Update changelog for #6858

CHANGELOG.md

@@ -12,6 +12,7 @@ IMPROVEMENTS:
 * `azurerm_eventgrid_event_subscription` - support for the `expiration_time_utc`, `service_bus_topic_endpoint`, and `service_bus_queue_endpoint`, property [GH-6860]
 * `azurerm_eventgrid_event_subscription` - the `eventhub_endpoint` was deprecated in favour of the `eventhub_endpoint_id` property [GH-6860]
 * `azurerm_eventgrid_event_subscription` - the `hybrid_connection_endpoint` was deprecated in favour of the `hybrid_connection_endpoint_id` property [GH-6860]
+* `azurerm_eventgrid_topic` - support for `input_schema`, `input_mapping_fields`, and `input_mapping_default_values` [GH-6858]
 * `azurerm_kubernetes_cluster` - exposing the `oms_agent_identity` block within the `addon_profile` block [GH-7056]
 * `azurerm_logic_app_action_http` - support for the `run_after` property [GH-7079]