Updated endpoints.json and partitions.json.

Author: AWS

.changes/next-release/feature-AWSSDKforJavav2-0443982.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Updated endpoint and partition metadata."
+}

core/regions/src/main/resources/software/amazon/awssdk/regions/internal/region/endpoints.json

@@ -16974,6 +16974,7 @@
           "ap-southeast-3" : { },
           "ap-southeast-4" : { },
           "ap-southeast-5" : { },
+          "ap-southeast-6" : { },
           "ap-southeast-7" : { },
           "ca-central-1" : {
             "variants" : [ {