ui: Fix modals not using UI font and text color (#50208)
Anthony Eid
created
The bug occurred because we weren't setting the right text style on the
root div anymore (Multiworkspace), which was introduce in #49995
### Before
<img width="3248" height="2122" alt="image"
src="https://github.com/user-attachments/assets/eca71731-5009-4e47-a948-d80eb3f13938"
/>
### After
<img width="3248" height="2122" alt="image"
src="https://github.com/user-attachments/assets/75d8c591-f539-413e-a171-71e4fc847f13"
/>
Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
Release Notes:
- N/A