Update endpoints model

Author: AWS SDK for Go v2 automation user

codegen/smithy-aws-go-codegen/src/main/resources/software/amazon/smithy/aws/go/codegen/endpoints.json

@@ -11120,6 +11120,7 @@
  "ap-southeast-2" : { },
  "ap-southeast-3" : { },
  "ap-southeast-4" : { },
+ "ap-southeast-5" : { },
  "ca-central-1" : { },
  "ca-west-1" : { },
  "eu-central-1" : { },