Update changelog based on model updates

Author: aws-sdk-python-automation

.changes/next-release/api-change-ecs-26621.json

@@ -0,0 +1,5 @@
+{
+  "type": "api-change",
+  "category": "``ecs``",
+  "description": "This release removes hookDetails for the Amazon ECS native blue/green deployments."
+}