This is currently not possible. If enabled, it would help a lot of users who rely on OneNote.
See this community discussion dating back 5 years with no resolution.
Agreed - whatever metadata is in OneNote which must be copied (hidden) into the Clipboard needs to be identified by SS and converted to plain text. I can copy text from OneNote and paste directly into Notepad—which is a very basic text editor—and it is recognized easily. So we need SS to put a little engineering prowess into decoding the clipboard content after OneNote is copied so that a paste operation inside SS pastes simply the text.