Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

crates/workspace/src/item.rs

@@ -489,7 +489,7 @@ where
     fn should_serialize(&self, event: &dyn Any, cx: &App) -> bool {
         event
             .downcast_ref::<T::Event>()
-            .map_or(false, |event| self.read(cx).should_serialize(event))
+            .is_some_and(|event| self.read(cx).should_serialize(event))
     }
 }