Add cgk region in pytorch.json file

Author: RadhikaB-97

src/sagemaker/image_uri_config/pytorch.json

@@ -39,6 +39,7 @@
                 "registries": {
                     "ap-northeast-1": "763104351884",
                     "ap-northeast-2": "763104351884",
+                    "ap-southeast-3": "907027046896",
                     "eu-west-1": "763104351884",
                     "us-east-1": "763104351884",
                     "us-east-2": "763104351884",