migrator: Remove text thread settings migration (#52889)

Since this was just removing unused keys, but behavior isn't broken if
they are there. So we can just leave them as-is


Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- N/A

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: MrSubidubi <dev@bahn.sh>
224ce68200Ben Brandt committed on 4/1/2026, 9:59:07 AM· committed by GitHubparent02e8914
3 files changedLine totals unavailable