fix: Pipeline.upsert() TypeError (real agent 1773874470) (#66666)

[aviruthen]

Description

The Pipeline methods create(), update(), and upsert() accept role_arn typed as str but perform no type validation. When a non-string value like a dict is passed, it flows through resolve_value_from_config() unchanged and eventually causes an unhelpful TypeError deep in the API call. The fix is to add a _validate_role_arn() helper that raises a clear ValueError if role_arn is not a string or None, and call it at the top of create(), update(), and upsert() before any other processing.

Related Issue

Fixes #66666

Changes Made

• src/sagemaker/workflow/pipeline.py
• tests/unit/sagemaker/workflow/test_pipeline.py

AI-Generated PR

This PR was automatically generated by the PySDK Issue Agent.

• Confidence score: 80%
• Classification: bug
• SDK version target: V2

Merge Checklist

• Changes are backward compatible
• Commit message follows prefix: description format
• Unit tests added/updated
• Integration tests added (if applicable)
• Documentation updated (if applicable)