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/prompt_store/src/prompt_store.rs

@@ -247,9 +247,7 @@ impl PromptStore {
 
             if metadata_db
                 .get(&txn, &prompt_id_v2)?
-                .map_or(true, |metadata_v2| {
-                    metadata_v1.saved_at > metadata_v2.saved_at
-                })
+                .is_none_or(|metadata_v2| metadata_v1.saved_at > metadata_v2.saved_at)
             {
                 metadata_db.put(
                     &mut txn,