[release-2.0] fix: the global search keyboard event is not removed wh…

…en the component is unmounted (#772)

This is an automated cherry-pick of #767

/assign JohnNiang

```release-note
None
```

src/layouts/BasicLayout.vue

@@ -81,7 +81,7 @@ onMounted(() => {
 });
 
 onUnmounted(() => {
-  document.addEventListener("keydown", handleGlobalSearchKeybinding);
+  document.removeEventListener("keydown", handleGlobalSearchKeybinding);
 });
 
 // Generate menus by routes