defensive guard for dict instances

reaction to:

    |   File "/galaxy/lib/galaxy/managers/histories.py", line 685, in get_record_metadata
    |     export_metadata = ExportObjectMetadata.parse_raw(json_metadata) if json_metadata else None
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |   File "/galaxy/.venv/lib/python3.12/site-packages/pydantic/main.py", line 1388, in parse_raw
    |     raise pydantic_core.ValidationError.from_exception_data(cls.__name__, [error])
    | pydantic_core._pydantic_core.ValidationError: 1 validation error for ExportObjectMetadata
    | __root__
    |   the JSON object must be str, bytes or bytearray, not dict [type=type_error, input_value={'request_data': {'object...41/150mb9.rocrate.zip'}}, input_type=dict]

Author: martenson

lib/galaxy/managers/histories.py

@@ -680,7 +680,12 @@ def create_export_association(self, history_id: int) -> model.StoreExportAssocia
 
     def get_record_metadata(self, export: model.StoreExportAssociation) -> Optional[ExportObjectMetadata]:
         json_metadata = export.export_metadata
-        export_metadata = ExportObjectMetadata.parse_raw(json_metadata) if json_metadata else None
+        if not json_metadata:
+            return None
+        if isinstance(json_metadata, dict):
+            export_metadata = ExportObjectMetadata.model_validate(json_metadata)
+        else:
+            export_metadata = ExportObjectMetadata.parse_raw(json_metadata)
         return export_metadata
 
     def _serialize_task_export(self, export: model.StoreExportAssociation, history: model.History):