Fix panic or bad hunks when expanding hunks w/ multiple ranges in 1 hunk (#28117)

Release Notes:

- Fixed a crash that could happen when expanding diff hunks with
multiple cursors in one hunk.
156dd32a35Max Brunsfeld committed on 4/4/2025, 7:22:02 PM· committed by GitHubparent2747915
2 files changedLine totals unavailable