Fix auto-indent when pasting multi-line content that was copied start… (#26246)

Closes https://github.com/zed-industries/zed/issues/24914 (again)

Release Notes:

- Fixed an issue where multi-line pasted content was auto-indented
incorrectly if copied from the middle of an existing line.
be75f17429Max Brunsfeld committed on 3/6/2025, 10:13:34 PM· committed by GitHubparentf373383
8 files changedLine totals unavailable