feat(clients): update client endpoints as of 2026-02-18

Author: awstools

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

@@ -21899,6 +21899,7 @@
               },
               "hostname": "portal.sso.ap-southeast-5.amazonaws.com"
             },
+            "ap-southeast-6": {},
             "ap-southeast-7": {},
             "ca-central-1": {
               "credentialScope": {