As of now, the spacing in Notes is double-spaced. It is more beneficial to have notes single spaced so it's easier to read and doesn't look like multiple rows/paragraphs.
Please roll out the same editor, with more functionalities like list, paragraph etc., as on this page for the Note section.
For single spacing, you have to press shift+enter every time
Even on single-spaced text that gets pasted into the notes gets turned to double spaced