Remove Flatpak warning now that sandboxing is reverted (#55673)

Self-Review Checklist:

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

Closes #ISSUE

Release Notes:

- N/A
c3a3eeafadConrad Irwin committed on 5/4/2026, 4:22:19 PM· committed by GitHubparent42f9420
1 file changedLine totals unavailable