Enable Service Principal authentication for notebookutils.udf metadata lookups in Fabric Pipeline

Currently, Microsoft Fabric pipeline notebook activities fail with a "401 Unauthorized" error when using notebookutils.udf methods (such as getFunctions or getMetadataStr) under a Service Principal identity. While these functions work when executed under a personal user identity, this limitation prevents automated pipelines from leveraging User Defined Functions (UDFs) for modular code sharing and reusability.

I hope Microsoft adds support for Service Principal identity contexts during UDF metadata retrieval, enabling more robust and automated code management within Fabric pipelines.