Reland "Remove cx from ThemeSettings" (#39720)

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

Closes #ISSUE

Release Notes:

- N/A

crates/journal/src/journal.rs

@@ -33,7 +33,7 @@ pub struct JournalSettings {
 }
 
 impl settings::Settings for JournalSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let journal = content.journal.clone().unwrap();
 
         Self {