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:
-
563d5dcee7
-
64f8aa0fb1
-
70b35712a2

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

Release Notes:

- N/A

crates/gpui/Cargo.toml

@@ -61,7 +61,7 @@ slotmap = "1.0.6"
 smallvec.workspace = true
 smol.workspace = true
 sum_tree.workspace = true
-taffy = { git = "https://github.com/DioxusLabs/taffy", rev = "1876f72bee5e376023eaa518aa7b8a34c769bd1b" }
+taffy = "0.4.3"
 thiserror.workspace = true
 time.workspace = true
 util.workspace = true