Disable diff hunks for untracked files, even w/ no newline at eof (#25980)

This fixes an issue where diff hunks were shown for untracked files, but
only if the files did not end with a newline.

Release Notes:

- N/A
563baf682eMax Brunsfeld committed on 3/4/2025, 6:18:27 AM· committed by GitHubparent11b79d0
4 files changedLine totals unavailable