fixed framework_version from 2.3 to 2.3.1

Author: adtian2

src/sagemaker/image_uri_config/pytorch-smp.json

@@ -8,7 +8,7 @@
             "2.1": "2.1.2",
             "2.2": "2.3.1",
             "2.2.0": "2.3.1",
-            "2.3": "2.4.0"
+            "2.3.1": "2.4.0"
         },
         "versions": {
             "2.0.1": {