editor: Make kill ring cut at EOF a no-op (#39069)

Release Notes:

- Emacs's kill ring cut at the end of the last line of the file will now
no-op instead of cutting the entire line
163219af35AidanV committed on 9/29/2025, 2:55:38 PM· committed by GitHubparentf96fd92
2 files changedLine totals unavailable