Fix InvenioRDM draft file upload

• wrap the file IO in a context manager to close it once it's not needed anymore
• call set_content() only on the file in question, not all files for the draft (that have likely already been committed)
• override the _data property of the outgoing stream to prevent the requests library from doing its magic

vre_repository_connector/api/inveniordm.py

@@ -144,14 +144,20 @@ class InvenioRDM(BaseWrapper):
         try:
             draft.get()
             file_meta = FilesListMetadata([{"key": file_name}])
-            file = draft.files.create(file_meta)
-
-            stream = open(file_path, "rb")
-            for f in draft.files:
-                f.set_contents(OutgoingStream(data=stream))
-                f.commit()
-
-            return (record_pid, file.data["entries"][0]["key"])
+            files_list = draft.files.create(file_meta)
+            file = files_list(file_name)
+
+            with open(file_path, "rb") as stream:
+                # NOTE: The `OutgoingStream` constructor turns the keyword arguments
+                #       into a dictionary which gets passed to `requests`, which
+                #       then uses form-urlencoding rather than an octet-stream.
+                #       To prevent this, we override the `_data` property.
+                out_stream = OutgoingStream()
+                out_stream._data = stream
+                file.set_contents(out_stream)
+                file.commit()
+
+            return (record_pid, file.data["key"])
 
         except Exception as e:
             print(f"File upload failed: {e}")