Fix `editor::SplitSelectionIntoLines` adding an extra line at the end (#25053)

Closes #4795

Release Notes:

- Fixed `editor::SplitSelectionIntoLines` adding an extra line at end
of selection
a8de6af641João Marcos committed on 2/18/2025, 3:23:48 AM· committed by GitHubparent12aa270
3 files changedLine totals unavailable