Fix relative indentation when pasting content copied from outside Zed (#25300)

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

Release Notes:

- Fixed incorrect indentation when pasting multi-line content that was
copied from another app.
c31c638006Max Brunsfeld committed on 2/21/2025, 1:25:33 AM· committed by GitHubparentee1a559
8 files changedLine totals unavailable