chore: Bump taffy version to 0.4.3 (#11606)

Taffy 0.4 has been released 2 months ago. We've been using an older
commit from their 0.4 development branch since November.
Compared to the commit we were pinned to, the following relevant changes
have been made:
-
https://github.com/DioxusLabs/taffy/commit/563d5dcee7b9138b4c3f865155d036a8b7597e65
-
https://github.com/DioxusLabs/taffy/commit/64f8aa0fb114d939ca0d53ddc44045a03fde548d
-
https://github.com/DioxusLabs/taffy/commit/70b35712a2e79b6fdfef4cff4392ca94287cd0b1

![image](https://github.com/zed-industries/zed/assets/24362066/ffdfae03-2743-496f-bb21-7aa38462178f)

Release Notes:

- N/A