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

@@ -21110,6 +21110,7 @@
           "ap-east-1" : { },
           "ap-northeast-1" : { },
           "ap-northeast-2" : { },
+          "ap-northeast-3" : { },
           "ap-south-1" : { },
           "ap-southeast-1" : { },
           "ap-southeast-2" : { },