fix(core): fix deadlock in on_menu_event, closes #5254 (#5257)

Author: amrbashir

Diff for: .changes/menu-deadlock.md

@@ -0,0 +1,5 @@
+---
+"tauri": "patch"
+---
+
+Fix a deadlock when modifying the menu in the `on_menu_event` closure.

Diff for: core/tauri/src/window.rs

@@ -773,14 +773,13 @@ impl<R: Runtime> Window<R> {
   pub fn on_menu_event<F: Fn(MenuEvent) + Send + 'static>(&self, f: F) -> uuid::Uuid {
     let menu_ids = self.window.menu_ids.clone();
     self.window.dispatcher.on_menu_event(move |event| {
-      f(MenuEvent {
-        menu_item_id: menu_ids
-          .lock()
-          .unwrap()
-          .get(&event.menu_item_id)
-          .unwrap()
-          .clone(),
-      })
+      let id = menu_ids
+        .lock()
+        .unwrap()
+        .get(&event.menu_item_id)
+        .unwrap()
+        .clone();
+      f(MenuEvent { menu_item_id: id })
     })
   }
 }