Merge branch 'devin/1751064114-fix-primary-key-fallback' of https://github.com/airbytehq/airbyte-python-cdk into devin/1751064114-fix-primary-key-fallback

Author: aaronsteers

airbyte_cdk/sql/shared/catalog_providers.py

@@ -120,11 +120,14 @@ def get_primary_keys(
         self,
         stream_name: str,
     ) -> list[str] | None:
-        """Return the primary keys for the given stream.
+        """Return the primary key column names for the given stream.
 
         We return `source_defined_primary_key` if set, or `primary_key` otherwise. If both are set,
         we assume they should not should differ, since Airbyte data integrity constraints do not
         permit overruling a source's pre-defined primary keys. If neither is set, we return `None`.
+        
+        Returns:
+            A list of column names that constitute the primary key, or None if no primary key is defined.
         """
         configured_stream = self.get_configured_stream_info(stream_name)
         pks = configured_stream.stream.source_defined_primary_key or configured_stream.primary_key