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/zed/src/zed.rs

@@ -1625,7 +1625,7 @@ fn open_local_file(
                     .await
                     .ok()
                     .flatten()
-                    .map_or(false, |metadata| !metadata.is_dir && !metadata.is_fifo);
+                    .is_some_and(|metadata| !metadata.is_dir && !metadata.is_fifo);
                 file_exists
             };
 

crates/zed/src/zed/migrate.rs

@@ -177,7 +177,7 @@ impl ToolbarItemView for MigrationBanner {
             }));
         }
 
-        return ToolbarItemLocation::Hidden;
+        ToolbarItemLocation::Hidden
     }
 }
 

crates/zed/src/zed/quick_action_bar.rs

@@ -175,9 +175,9 @@ impl Render for QuickActionBar {
                 let code_action_menu = menu_ref
                     .as_ref()
                     .filter(|menu| matches!(menu, CodeContextMenu::CodeActions(..)));
-                code_action_menu.as_ref().map_or(false, |menu| {
-                    matches!(menu.origin(), ContextMenuOrigin::QuickActionBar)
-                })
+                code_action_menu
+                    .as_ref()
+                    .is_some_and(|menu| matches!(menu.origin(), ContextMenuOrigin::QuickActionBar))
             };
             let code_action_element = if is_deployed {
                 editor.update(cx, |editor, cx| {