fix(jumpstart): name JumpStart in the content bucket error (#6243)

`get_jumpstart_content_bucket` named Neo in its error for a region without a JumpStart entry. In v2 this message is the user-visible failure for `deepseek-llm-r1-distill-llama-8b` in `eusc-de-east-1` (#6242). Name JumpStart in the error.

---
X-AI-Prompt: What is the minimal source change that fixes the EU Sovereign Cloud JumpStart error?
X-AI-Tool: claude-code

Co-authored-by: papriwal <papriwal@amazon.com>

Author: evakravi

sagemaker-core/src/sagemaker/core/jumpstart/utils.py

@@ -204,7 +204,7 @@ def get_jumpstart_content_bucket(
         except KeyError:
             formatted_launched_regions_str = get_jumpstart_launched_regions_message()
             raise ValueError(
-                f"Unable to get content bucket for Neo in {region} region. "
+                f"Unable to get content bucket for JumpStart in {region} region. "
                 f"{formatted_launched_regions_str}"
             )
 

sagemaker-core/tests/unit/test_jumpstart_utils.py

@@ -491,7 +491,7 @@ def test_get_jumpstart_content_bucket_with_override(self):
     def test_get_jumpstart_content_bucket_invalid_region(self):
         """Test with invalid region"""
         with patch.object(constants, "JUMPSTART_REGION_NAME_TO_LAUNCHED_REGION_DICT", {}):
-            with pytest.raises(ValueError, match="Unable to get content bucket for Neo"):
+            with pytest.raises(ValueError, match="Unable to get content bucket for JumpStart"):
                 utils.get_jumpstart_content_bucket("invalid-region")