Reland "Remove cx from ThemeSettings" (#39720)

- **Reapply "Remove cx from ThemeSettings (#38836)" (#39691)**
- **Fix theme loading races**

Closes #ISSUE

Release Notes:

- N/A

crates/project/src/project.rs

@@ -980,7 +980,7 @@ pub struct DisableAiSettings {
 }
 
 impl settings::Settings for DisableAiSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         Self {
             disable_ai: content.disable_ai.unwrap().0,
         }